Abstract. Striga is a root parasite of m a n y f o o d c r o p s. It c a u s e s
|
|
- Polly Bell
- 5 years ago
- Views:
Transcription
1
2 Abstract R a m a i a h, K.V., Parker, C., V a s u d e v a R a o. M.J., a n d M u s s e l m a n, L.J Striga identification a n d c o n t r o l handbook. Information Bulletin No. 15. P a t a n c h e r u, A.P., India: International C r o p s R e s e a r c h Institute for t h e S e m i - A r i d T r o p i c s. Striga is a root parasite of m a n y f o o d c r o p s. It c a u s e s serious yield losses throughout the s e m i - a r i d tropics. T h e purpose of this bulletin is to c r e a t e i n c r e a s e d a w a r e n e s s o f t h e n e e d t o r e d u c e s u c h l o s s e s associated with Striga infestations. It d e s c r i b e s t h e most important of the 25 s p e c i e s of t h e w e e d o c c u r r i n g in the world, their biology, a n d s y m p t o m s of attack. It also provides brief information a b o u t the options for controlling the parasite. A key is p r e s e n t e d to assist in the identification of the s e v e n m o s t d a m a g i n g s p e c i e s of Striga, a n d the text is s u p p o r t e d by 34 illustrations in color. The International Crops Research Institute lor the Semi-Arid Tropics (ICRISAT) is a nonprofit scientific educational institute receiving support from donors through the Consultative Group on International Agricultural Research. Donors to ICRISAT include governments and agencies of Australia, Belgium, Canada, Federal Republic of Germany, France. India, Italy, Japan, Mexico, the Netherlands, New Zealand, Nigeria, Norway, Sweden, Switzerland, United Kingdom, United Slates, and the following international and private organizations: Asian Development Bank, European Economic Community, Ford Foundation, International Bank for Reconstruction and Development, International Development Research Centre, International Fertilizer Development Center, Internalional Fund for Agricultural Development, Leverhulme Trust, Organization of Petroleum Exporting Countries, Rockefeller Foundation, and the United Nations Development Programme. Responsibility for the information in this publication rests with ICRISAT. Where trade names are used this does not constitute endorsement of or discrimination against any product by the Institute. Correct citation: RAMAIAH, K.V., PARKER, C, VASUDEVA RAO, M.J., and MUSSELMAN, L.J Striga identification and control handbook. Information Bulletin No. 15. Patancheru, A.P., India: International Crops Research Institute for the Semi-Arid Tropics.
3 STRIGA IDENTIFICATION AND CONTROL HANDBOOK K.V. R a m a i a h I C R I S A T, B.P , O u a g a d o u g o u, U p p e r Volta W e s t A f r i c a C. P a r k e r W e e d R e s e a r c h O r g a n i z a t i o n, B e g b r o k e Hill, Y a m t o n, O x f o r d, O X 5 1PF, U K M. J. V a s u d e v a R a o I C R I S A T C e n t e r, P a t a n c h e r u P.O. A n d h r a P r a d e s h , India L.J. M u s s e l m a n O l d D o m i n i o n University, Norfolk, Virginia , U S A Published by the International Crops Research Institute tor the Semi-Arid Tropics with financial assistance from the International Development Research Centre (IDRC), Canada. ICRISAT Information Bulletin No. 15 International Crops Research Institute for the Semi-Arid Tropics ICRISAT Patancheru P.O. Andhra Pradesh , India 1983
4 Contents I N T R O D U C T I O N 3 B I O L O G Y S e e d s G e r m i n a t i o n H a u s t o r i a l i n i t i a t i o n A t t a c h m e n t N u t r i t i o n L i f e c y c l e STRIGA S P E C I E S Striga asiatica Striga hermonthica Striga densiflora K e y t o m a i n Striga s p e c i e s Striga euphrasioides Striga aspera Striga gesnerioides Striga forbesii S Y M P T O M S O F STRIGA A T T A C K 3 6 C O N T R O L M E A S U R E S R e s i s t a n t c u l t i v a r s Striga-pulling by h a n d R o t a t i o n s N i t r o g e n fertilizer H e r b i c i d e s G e r m i n a t i o n s t i m u l a n t s B i o c o n t r o l I n t e g r a t e d c o n t r o l P h o t o C r e d i t s 5 1
5 I N T R O D U C T I O N P l a n t s of Striga g e n u s ( S c r o p h u l a r i a c e a e ) a r e g e n e r a l l y k n o w n a s w i t c h w e e d s. T h e g e n u s i n c l u d e s a b o u t 2 5 s p e c i e s, o n l y a f e w o f w h i c h a r e e c o n o m i c a l l y i m p o r - tant, for i n s t a n c e S. hermonthica, S. asiatica, S. gesnerioides, S. densiflora, S. euphrasioides, S. aspera, a n d S. forbesii (in o r d e r o f i m p o r t a n c e ). S p e c i e s r a n g e f r o m a l m o s t c o m p l e t e l y p a r a s i t i c t o a l m o s t totally a u t o t r o - p h i c. T h e y a t t a c k s e v e r a l f o o d c r o p s, m a i n l y c e r e a l s, but a l s o s o m e b r o a d - l e a v e d c r o p s s u c h a s c o w p e a. T h e r e i s a w i d e r a n g e o f w i l d h o s t s. T h o u g h p r e c i s e c r o p l o s s e s t i m a t e s a r e difficult t o m a k e, c o m p l e t e c r o p failu r e s c a u s e d b y Striga h a v e b e e n r e c o r d e d, a n d o c c u r i n m a n y r e g i o n s o f A f r i c a a n d India. C o n t r o l o f Striga c o u l d not o n l y i n c r e a s e f o o d p r o d u c t i o n in Striga-infested l a n d, b u t a l s o b r i n g b a c k into c u l t i v a t i o n l a n d that w a s p r e s e n t l y a b a n d o n e d b e c a u s e of Striga i n f e s t a t i o n. U n f o r t u n a t e l y, Striga is still c o n s i d e r e d as a w e e d n u i s a n c e a n d n o t a s t h e i m p o r t a n t a g r i c u l t u r a l pest i t is. T h o u g h f a r m e r s w h o s e p l a n t s s u f f e r Striga a t t a c k r e c - o g n i z e it as a p r i m a r y y i e l d - r e d u c e r of t h e i r f o o d c r o p s, t h e e x t e n t o f t h e p r o b l e m h a s s o far not b e e n r e a l i z e d b y r e s e a r c h a n d e x t e n s i o n a g e n c i e s a n d t h e i r d o n o r s. A s a result, t h e r e is a g e n e r a l l a c k of a w a r e n e s s of t h e p r o b - l e m. T h e r e i s a l s o s o m e c o n f u s i o n i n t h e i d e n t i f i c a t i o n o f different Striga s p e c i e s. T h i s h a n d b o o k illustrates in c o l o r s o m e o f t h e e c o n o m i c a l l y i m p o r t a n t s p e c i e s a n d g i v e s i n f o r m a t i o n a b o u t t h e i r d i s t r i b u t i o n, h o s t r a n g e, a n d c o n t r o l m e a s u r e s 3
6 B I O L O G Y Seeds Striga s e e d s a r e p r o d u c e d i n e n o r m o u s n u m b e r s. E a c h s e e d c a p s u l e (Fig. 1 ) p r o d u c e s s o m e s e e d s, a n d e a c h p l a n t t h u s p r o d u c e s s e v e r a l t h o u s a n d s. T h e y a r e g e n e r a l l y d i s p e r s e d b y w i n d, w a t e r, c a t t l e, a n d m a n. S e e d s a r e m i n u t e, m e a s u r i n g a b o u t 0.2 x 0.3 m m ( s e e c e n t e r o f Fig. 2 ; for c o m p a r i s o n m a i z e s e e d s a r e s h o w n, t o p, a n d s o r g h u m s e e d s, b o t t o m : x 3 m a g n i f i c a t i o n ). All s p e c i e s o f Striga h a v e p r o m i n e n t r i d g e s o n t h e s e e d c o a t s u r f a c e t h a t c a n b e s e e n u n d e r t h e m i c r o s c o p e. T h e p r i m a r y r i d g e s a r e g e n e r a l l y o r n a m e n t e d. S e c o n d - a r y r i d g e s, w h i c h r u n a t v a r y i n g a n g l e s b e t w e e n p r i m a r y r i d g e s, m a y l a c k o r n a m e n t a t i o n. G e r m i n a t i o n Striga s e e d s p o s s e s s t h e r e m a r k a b l e c a p a c i t y t o r e m a i n v i a b l e i n t h e soil for y e a r s i n t h e a b s e n c e o f a s u i t a b l e p l a n t h o s t. T h e s e e d s a r e u s u a l l y d o r m a n t for a f e w m o n t h s a f t e r h a r v e s t b e f o r e t h e y a c q u i r e t h e c a p a c i t y t o g e r m i n a t e, b u t s o m e s a m p l e s h a v e b e e n s h o w n t o g e r m i n a t e m o r e q u i c k l y t h a n o t h e r s. A f t e r t h i s d o r m a n c y r e q u i r e m e n t i s s a t i s f i e d t h e s e e d s n e e d a p e r i o d o f c o n d i t i o n i n g. T h i s m a y l a s t s o m e d a y s u n d e r o p t i m u m m o i s t u r e a n d t e m p e r a t u r e c o n d i t i o n s b e f o r e t h e y r e s p o n d t o a g e r m i n a t i o n s t i m u l a n t p r o - d u c e d b y t h e y o u n g h o s t root. T h e s e e d s h a v e t o b e v e r y c l o s e t o t h e h o s t r o o t ( w i t h i n 1 0 m m a n d p r e f e r a b l y w i t h i n 3-4 m m ) t o b e s t i m u l a t e d. A t f a v o r a b l e t e m p e r a - t u r e s o f C, s e e d g e r m i n a t i o n o c c u r s w i t h i n 2 4 h o u r s ( F i g. 3 : x 2 5 ). 4
7 Figure 1 5
8 Figure 2 6
9 Figure 3 7
10 Haustorial initiation T h e r e a p p e a r s t o b e c h e m o t r o p i c b e h a v i o r t h a t a s s i s t s t h e p a r a s i t e i n m a k i n g c o n t a c t w i t h t h e host root. O n c o n t a c t w i t h t h e root, t h e tip o f t h e r a d i c l e t r a n s f o r m s itself into a h a u s t o r i u m ( a r r o w e d in Fig. 4), a p p a r e n t l y d u e t o a c h e m i c a l s e c r e t i o n f r o m t h e host root k n o w n a s t h e h a u s t o r i a l initiation f a c t o r. A t t a c h m e n t T h e r a d i c l e of t h e Striga s e e d l i n g s e c r e t e s e n z y m e s that assist in its p e n e t r a t i o n of t h e h o s t root. T h e x y l e m of t h e p a r a s i t e t h e n e s t a b l i s h e s c o n n e c t i o n s w i t h t h a t o f the host, t h u s c o m p l e t i n g t h e s u c c e s s f u l e s t a b l i s h m e n t o f the p a r a s i t e on t h e host (Figs. 5 a n d 6). C e r t a i n s p e c i e s of Striga c a n p r o d u c e a d v e n t i t i o u s r o o t s t h a t f o r m s e c o n d a r y h a u s t o r i a. T h u s t h e p a r a s i t e b e c o m e s c o n - n e c t e d to m a n y roots of t h e host w i t h i n a short t i m e. Nutrition O n c e e s t a b l i s h e d, t h e p a r a s i t e b e c o m e s a m e t a b o l i c sink for t h e c a r b o h y d r a t e s p r o d u c e d in t h e host, t h u s d e p r i v i n g the host of s o m e of its p h o t o s y n t h a t e s. T h e effect of Striga on t h e host, h o w e v e r, is m o r e t h a n just the r e m o v a l of water, assimilates, a n d other nutrients. R e c e n t s t u d i e s a t t h e U n i v e r s i t y o f R e a d i n g, U K, h a v e s h o w n that, as a result of Striga i n f e s t a t i o n, g r o w t h inhibitors i n t h e host a r e i n c r e a s e d a n d g r o w t h p r o m o - ters a r e d e c r e a s e d ( s u g g e s t i n g a n e x p l a n a t i o n o f t h e d a m a g i n g e f f e c t s of Striga on t h e h o s t ). Y o u n g Striga s e e d l i n g s are c o m p l e t e l y p a r a s i t i c o n t h e host w h i l e t h e y a r e s u b t e r r a n e a n a n d, a t this s t a g e, c a u s e m a x i - m u m d a m a g e t o t h e host. O n e m e r g e n c e f r o m t h e g r o u n d t h e y d e v e l o p g r e e n l e a v e s (Fig. 7 ) t h a t p r o d u c e their o w n p h o t o s y n t h a t e s. H o w e v e r, t h e r e i s a c o n - 8
11 Figure 4 9
12 Figure 5 a: S o r g h u m root b: Striga initial c: Striga h a u s t o r i u m 10
13 Figure 6 a: Striga leaf initial b: S u b t e r r a n e a n Striga 11
14 Figure 7 12
15 t i n u e d flow o f c a r b o h y d r a t e s, w a t e r, a n d m i n e r a l s f r o m t h e host. Life c y c l e After g e r m i n a t i o n a n d a t t a c h m e n t, Striga t a k e s a f e w w e e k s t o e m e r g e, d e p e n d i n g u p o n t h e d e p t h o f t h e s e e d i n t h e soil. A f t e r e m e r g e n c e, i t t a k e s a b o u t w e e k s t o c o m p l e t e its life c y c l e. T h u s, 2-4 m o n t h s a r e r e q u i r e d f r o m g e r m i n a t i o n to s e e d - s e t t i n g. It is o f t e n o b s e r v e d that Striga c a n c o m p l e t e its life c y c l e on t h e c r o p s t u b - ble after t h e h a r v e s t of t h e host. 13
16 STRIGA S P E C I E S T h e e c o n o m i c a l l y i m p o r t a n t Striga s p e c i e s a r e all a n n u - als. T h e g e n u s i s c h a r a c t e r i z e d b y o p p o s i t e l e a v e s a n d irregular f l o w e r s w i t h a p r o n o u n c e d b e n d in t h e c o r o l l a tube ( see K e y to the main Striga species, pp ). 1. Striga asiatica (L.) K u n t z e ( = S. lutea L o u r. = S. hirsuta B e n t h. = S. coccinea B e n t h. ) S. asiatica is a s e l f - p o l l i n a t e d s p e c i e s w i t h e s t a b l i s h e d m o r p h o l o g i c a l d i f f e r e n c e s a m o n g strains ( m o r p h o - t y p e s ) p r e s e n t in different g e o g r a p h i c a l r e g i o n s of t h e s e m i - a r i d tropics. In India, it is u s u a l l y w h i t e - f l o w e r e d (Fig. 8). I n I n d o n e s i a s e v e r a l d i s t i n c t f o r m s h a v e b e e n o b s e r v e d, i n c l u d i n g o n e w i t h p a l e - p i n k f l o w e r s (Fig. 9 ) and another with yellow flowers (Fig. 10). A y e l l o w - flowered variant w a s also f o u n d in North Carolina in the USA, Upper Volta ( West Africa), a n d in South Africa. In S o u t h A f r i c a the s p e c i e s h a s bright r e d f l o w e r s w i t h a y e l l o w c o l o r o n t h e u n d e r s u r f a c e o f t h e c o r o l l a (Fig. 11) a n d, in the U S A, a d e e p r e d f l o w e r (Fig. 12). D i s t i n g u i s h i n g f e a t u r e s. Plants of this s p e c i e s are extremely variable, slender erect herbs, s c a b r i d - p u b e s c e n t o r a l m o s t g l a b r o u s, w i t h g l a n d u l a r p u b e s - cent b u d s. C a l y x - l o b e s s u b u l a t e, c a l y x distinctly 10- ribbed, usually hispid; corolla t u b e up to 10 mm long, g l a n d u l a r p u b e s c e n t, a n d c o r o l l a m m d i a m e t e r ; bracts linear- lanceolate, a b o u t 5 mm long. D i s t r i b u t i o n. It is w i d e s p r e a d in t h e s e m i - a r i d t r o p i c a l regions of A s i a, s o u t h e r n A f r i c a ( f r o m L a k e V i c t o r i a in T a n z a n i a to S o u t h A f r i c a ), a n d is a l s o e s t a b l i s h e d in North a n d South Carolina, USA. Additionally, it has b e e n r e c o r d e d f r o m n o r t h e r n t r o p i c a l A f r i c a, but rarely a s a n a g r i c u l t u r a l p r o b l e m. 14
17 Figure 8 15
18 Figure 9 16
19 Figure 10 17
20 Figure 11 18
21 Figure 12 19
22 H o s t r a n g e. A l m o s t all c e r e a l c r o p s : s o r g h u m, p e a r l millet, m a i z e, f i n g e r a n d foxtail millet, a n d u p l a n d r i c e ; a l s o s u g a r c a n e, Paspalum, a n d g r a s s w e e d s f o r e x a m p l e Digitaria sanguinalis. H o s t s p e c i f i c i t y. S o r g h u m - a n d m i l l e t - s p e c i f i c s t r a i n s of S. asiatica h a v e b e e n r e p o r t e d f r o m India. 2. Striga hermonthica ( D e l. ) B e n t h. ( = S. senegalensis B e n t h. ) S. hermonthica (Fig. 13) is a c r o s s - p o l l i n a t e d s p e c i e s. Pollination i s e f f e c t e d b y i n s e c t s, i n c l u d i n g b u t t e r f l i e s (Fig. 14) a n d m o t h s that s u c k n e c t a r f r o m t h e b a s e o f t h e l o n g c o r o l l a t u b e. B e e - f l i e s ( B o m b y l i i d s ) a r e o f t e n f o u n d visiting t h e f l o w e r s t o f e e d o n p o l l e n, but m a y not b e e f f e c t i v e p o l l i n a t o r s. L o n g - t o n g u e d l e p i d o p t e r a n s a r e c o n s i d e r e d a s t h e m o s t likely p o l l i n a t o r s. C r o s s - p o l l i n a t i o n r e s u l t s in a c o n t i n u o u s v a r i a t i o n in this s p e - c i e s w h e r e a s, in S. asiatica, t h e s p o n t a n e o u s m u t a t i o n s m a y be fixed by self- pollination. In S. hermonthica w i d e v a r i a t i o n h a s b e e n r e c o r d e d for plant t y p e, c o r o l l a s h a p e, size, a n d c o l o r (Fig. 15). W h i t e - f l o w e r e d p l a n t s a r e o c c a s i o n a l l y s e e n a t v e r y l o w f r e q u e n c y. T h e y a r e p r o b a b l y s p o n t a n e o u s r e c e s s i v e m u t a n t s. D i s t i n g u i s h i n g f e a t u r e s. E r e c t h e r b r e a c h i n g a h e i g h t of 0.5 m; f l o w e r s bright pink; c a l y x d i s t i n c t l y f i v e - r i b b e d ; c o r o l l a t u b e m m i n l e n g t h, b e n d i n g c h a r - a c t e r i s t i c a l l y a t a n a n g l e i m m e d i a t e l y o v e r t h e tip o f t h e c a l y x. D i s t r i b u t i o n. W i d e s p r e a d i n t h e s e m i - a r i d z o n e s o f n o r t h e r n t r o p i c a l A f r i c a f r o m 5 S u p t o 2 0 N l a t i t u d e. F r o m e a s t to w e s t it is d i s t r i b u t e d a c r o s s t h e w i d t h of A f r i c a. It is not r e p o r t e d f r o m o t h e r p l a c e s in t h e w o r l d, e x c e p t t h e s o u t h w e s t A r a b i a n p e n i n s u l a. 2 0
23 Figure 13 21
24 Figure 14 22
25 Figure 15 H o s t r a n g e. S o r g h u m (Fig. 16), pearl millet (Fig. 17), maize, u p l a n d rice, finger millet, s u g a r c a n e, a n d s e v e r a l wild grasses in fallow lands a n d field bunds. H o s t specificity. At least t w o c r o p - s p e c i f i c strains exist in West Africa. O n e is specific to pearl millet in the drier zone north of latitude 13 N, w h e r e it d o e s not parasitize s o r g h u m (Fig. 18). T h e s e c o n d strain f o u n d in the north Sudanian zone, a r o u n d latitude 12 N, attacks s o r g h u m but not pearl millet. Maize, however, appears to be g e n e r a l l y s u s c e p t i b l e to this s p e c i e s. 3. Striga densiflora B e n t h. Striga densiflora is relatively less i m p o r t a n t as a s p e c i e s c o m p a r e d with S. aslatica a n d S. hermonthica, a n d is often m i s t a k e n for t h e w h i t e - f l o w e r e d S. asiatica. S. densiflora f o u n d on g r a s s e s is short ( u p to 0.2 m), w h i l e on s o r g h u m a n d m a i z e it c a n r e a c h a height of up to 1 m. 23
26 Figure 16 24
27 Figure
28 Key to the main Striga species 1a. 1b. C a l y x ribs 5 2 2a. 2 b L e a v e s s c a l e - l i k e ; rarely e x c e e d i n g 5 mm in length. Corolla v a r i a b l e in color: w h i t e / m a u v e / p i n k / purple, 3-5 m m a c r o s s ; d e n s e l y b r a n c h e d p a r a - site on cowpea but usually less branched forms on other hosts... S. gesnerioides Leaves green, mm long: a. 3 b. Corolla white, m m a c r o s s ; a n t h e r s b l u i s h - black; plants s p a r s e l y b r a n c h e d, drying bluish S. densiflora C o r o l l a p i n k / m a u v e, m m a c r o s s 4 4a. 4b. C o r o l l a tube about equal to c a l y x in length ( c a 10 m m ) bent i m m e d i a t e l y a b o v e calyx; b r a c t e o l e 2-3 mm w i d e S. hermonthica Corolla t u b e m m long, distinctly longer t h a n 5a. C a l y x ribs 10 or m o r e, but n e v e r m o r e t h a n 5 e x t e n d i n g t o t i p s o f c a l y x l o b e s, r e m a i n d e r s t o p p i n g a t t h e s i n u s ; c o r o l l a m m a c r o s s ; 5b. 6a. 6b. C a l y x ribs 15, t h r e e m e e t i n g at the tip of e a c h calyx lobe 6 L e a v e s narrowly l a n c e o l a t e, 3-8 m m w i d e without teeth; corolla white, m m a c r o s s ; s e e d s 0.5 mm long S. euphrasioides L e a v e s broadly l a n c e o l a t e m m w i d e, c o a r s e l y t o o t h e d ; c o r o l l a s a l m o n - p i n k ( r a r e l y y e l l o w ), 26 27
29 28
30 D i s t i n g u i s h i n g f e a t u r e s. Robust, little b r a n c h e d, a n d erect herb; aerial parts profusely hairy, g r e e n or purple, t u r n i n g d a r k b l u e o n d r y i n g ; f l o w e r s d e n s e l y a r r a n g e d o n t h e i n f l o r e s c e n c e ( h e n c e t h e n a m e densiflora); f l o w e r s bright w h i t e ; c a l y x f i v e - r i b b e d ( u n l i k e S. asiatica that h a s 10 ribs). A n o t h e r distinguishing feature is the anther color, w h i c h is c r e a m y w h i t e in S. asiatica a n d d a r k blue in S. densiflora. S e e d s a r e s i m i l a r in size to S. asiatica but u s u a l l y a r e d a r k e r b r o w n w i t h t h e n a r r o w e n d blunt rather t h a n p o i n t e d. F i g u r e 1 9 s h o w s a c o m p a r i s o n b e t w e e n p l a n t s of S. densiflora (on t h e left), a n d S. asiatica (right). D i s t r i b u t i o n. S. asiatica a n d S. densiflora a r e f o u n d together in s o m e parts of India. M i x e d populations of the t w o s p e c i e s a r e often s e e n i n s o r g h u m fields i n M a h a - r a s h t r a, K a r n a t a k a, a n d G u j a r a t s t a t e s in India. In o t h e r parts of India S. densiflora is f o u n d on wild grasses. H o s t r a n g e. S o r g h u m, m a i z e, millets, a n d w i l d g r a s s e s. 4. Striga euphrasioides B e n t h. ( = S. angustifolia ( D o n ) S a l d h a n a ) S. euphrasioides is less parasitic t h a n the previously d e s c r i b e d s p e c i e s, b e i n g c a p a b l e o f g e r m i n a t i o n a n d p o s s i b l y e v e n o f g r o w i n g t o a n a d v a n c e d s t a g e i n t h e a b s e n c e o f t h e host ( t h o u g h t h e r e i s d i s a g r e e m e n t o n this). D i s t i n g u i s h i n g f e a t u r e s. S m a l l e r e c t h e r b r e a c h i n g a m a x i m u m height of 0.45 m; white flowers in long lax t e r m i n a l s p i k e s ( s e e Fig. 2 0, c e n t e r ; on t h e left, S. a s i a - tica; right, S. densiflora); calyx ribbed, unlike other s p e c i e s ; c a p s u l e w a l l s m u c h s t r o n g e r ; c a l y x r e m a i n s w i t h t h e s p i k e for a c o n s i d e r a b l e t i m e after s e e d d i s p e r - sal. S e e d s a r e d i s t i n c t l y larger (0.3 x 0.5 m m ) w i t h m o r e e l a b o r a t e s c u l p t u r i n g. 29
31 Figure 19 30
32 D i s t r i b u t i o n. India a n d B u r m a. H o s t r a n g e. S o r g h u m, maize, sugarcane, upland rice, a n d g r a s s w e e d s. Figure 20 31
33 5. Striga aspera (Willd.) B e n t h. (= Euphrasia aspera Willd.) Distinguishing features. It is similar to S. hermonthica except that it is smaller, the major distinguishing c h a r - acteristic being that the corolla tube has glandular hairs and e x t e n d s b e y o n d the tip of the calyx before it c h a r a c - teristically bends, w h e r e a s that of S. hermonthica is free from glands a n d the corolla t u b e b e n d s abruptly over the calyx tip (see Fig. 2 1, right; on the left, S. hermonthica). Distribution. Throughout West Africa and S u d a n. Host range. Upland rice, and wild grasses. Also, o c c a - sionally o b s e r v e d o n maize, s o r g h u m, a n d s u g a r c a n e. However, it is rarely an e c o n o m i c p r o b l e m. 6. Striga gesnerioides ( Willd.) V a t k e ( = S. orobanchoides B e n t h. ) S. gesnerioides is almost completely parasitic, a n d c o n - tains less chlorophyll than other s p e c i e s. Distinguishing features. Distinctly different f r o m other species. A large number of short b r a n c h e s arise from the g r o u n d level; c o m p a c t (Fig. 22); g r o w s to a height of 0.15 m; leaves scale- like; f o r m s a very large haustorium with the host root, unlike other s p e c i e s (see Fig. 23 that s h o w s a S. gesnerioides haustorium, arrowed right, attached to a c o w p e a root on the left); s p e c i e s s h o w s variation in flower size a n d color: f l o w e r s usually bluish, pink, purple, or c r e a m y white. Distribution. From C a p e Verde Islands through tropical and southern Africa and through the Arabian peninsula and western a n d southern India. Also f o u n d in Florida in the USA. 32
34 Figure 21 33
35 Figure 22 34
36 35
37 Host r a n g e. C o w p e a, t o b a c c o, Euphorbia, hairy indigo (Indigofera hirsuta) (Fig. 24), Jacquemontia tamnifolia, and other weedy Convolvulaceae, and the w e e d y l e g u m e Tephrosia pedicellata. A w i d e range of other hosts are reported. Host specificity. T h e f o r m s parasitizing c o w p e a, t o b a c c o, indigo, a n d Tephrosia h a v e e a c h b e e n s h o w n to be specific to t h e s e hosts. 7. Striga forbesii B e n t h. It is rarely an e c o n o m i c p r o b l e m. D i s t i n g u i s h i n g f e a t u r e s. Erect, s i m p l e o r littleb r a n c h e d herb g r o w i n g to a height of a b o u t 0.5 m; flowers pink (Fig. 25), scarlet, or yellow, mm diameter; corolla tube mm long, sparsely pubescent. This species c a n be distinguished from S. hermonthica by the p r e s e n c e of t w o f l o w e r s only o p e n on e a c h inflorescence, the salmon- pink colored corolla, a n d lobed leaves. Distribution. Throughout West a n d East Africa, South Africa a n d M a d a g a s c a r. Host r a n g e. Maize, s o r g h u m, rice, and Setaria sphacelata. SYMPTOMS OF STRIGA ATTACK In severe infestations s y m p t o m s of Striga attack generally b e c o m e o b s e r v a b l e e v e n before t h e Striga e m e r g e s from the soil. Both S. asiatica a n d S. hermonthica c a u s e stunting of the host shoot and failure of panicle f o r m a - 3 6
38 Figure 24 37
39 Figure 25 38
40 tion, but other s y m p t o m s are different for the two species. S. asiatica attack induces s y m p t o m s similar to t h o s e i n d u c e d by d r o u g h t - l i k e leaf wilting (Figs. 26 a n d 27) a n d leaf rolling, even though the soil is saturated with moisture. S. hermonthica does not generally c a u s e d r o u g h t s y m p t o m s but d o e s c a u s e chlorotic lesions (Fig. 28). T h e s e m a y not a l w a y s be c l e a r a n d are quite often c o n f u s e d with leaf d i s e a s e s. Striga m a y c o m - pletely d e s t r o y the host if d r o u g h t o c c u r s b e c a u s e drought a d d s to the water stress already created by Striga. Striga attack c a n be very serious on millets b e c a u s e millets are generally g r o w n on lighter soils under low a n d erratic rainfall, and the attack c a n lead to a c o m p l e t e loss of yield. S o r g h u m m a y also be badly a t t a c k e d on lighter soils with low rainfall (Fig. 29), but s h o w less d a m a g e in high-rainfall a r e a s, p r o b a b l y b e c a u s e of high soil fertility and moisture that favor g o o d c r o p g r o w t h a n d also d i s c o u r a g e Striga. S. gesnerioides c a n be a very s e r i o u s p a r a s i t e of c o w p e a, c a u s - ing chlorosis and then severe wilting and collapse under drought stress, very often leading to c o m p l e t e crop failure. CONTROL MEASURES No single control m e a s u r e currently available c a n provide c o m p l e t e c o n t r o l, a n d m a n y of t h o s e listed b e l o w have limited applicability on small farms. T h e identification, breeding, a n d distribution of resistant varieties are by far the most important research a n d developmental activities r e c o m m e n d e d, but other a g r o n o m i c control m e a s u r e s should be exploited wherever feasible. 39
41 Figure 26 40
42 Figure 27 41
43 Figure 28 42
44 43
45 R e s i s t a n t c u l t i v a r s The breeding of cultivars that are not parasitized, or are only lightly parasitized by Striga, offers a practical c o n - trol measure. A few resistant cultivars of s o r g h u m have already been identified. N - 13 f r o m India, a n d Framida (Fig. 30) f r o m S o u t h A f r i c a, for e x a m p l e, h a v e g o o d levels of r e s i s t a n c e. O t h e r useful cultivars i n c l u d e SPV 103, an i m p r o v e d c u l t i v a r f r o m India, a n d IS , a l o w - s t i m u l a n t variety f r o m S u d a n. T o l e r a n c e ( c a p a c i t y to yield well in spite of a high Striga infestation) has been exhibited by s e v e r a l l o c a l a n d i m p r o v e d cultivars of s o r g h u m. Very little information is available on breeding for resistance to Striga in maize, pearl millet, a n d c o w - pea. H o w e v e r, p r e l i m i n a r y results i n d i c a t e that t h e r e is g e n e t i c variability for host plant r e s i s t a n c e in pearl millet, and that Serere 2 A - 9 is less susceptible. Host r e s i s t a n c e to Striga is not b e l i e v e d to exist in maize b e c a u s e it is not native to A f r i c a. In p r e l i m i n a r y c o w p e a trials, t w o varieties, S u v i t a - l l ( G o r o m G o r o m local f r o m U p p e r Volta) a n d T N (an i m p r o v e d local f r o m Niger), h a v e exhibited a satisfactory level of resistance to S. gesnerioides. C r o p varieties resistant to Striga at specific l o c a t i o n s c a n b e r e q u e s t e d f r o m t h e a u t h o rs. Striga-pulling by h a n d It is not practical to hand- pull d e n s e infestations but s p a r s e infestations c a n be h a n d - p u l l e d b e f o r e Striga flowers. T h i s p r a c t i c e p r e v e n t s t h e p r o d u c t i o n of Striga s e e d s. S u c h h a n d - p u l l i n g s h o u l d c o n t i n u e b e y o n d c r o p harvest, if necessary. T h e c r o p stubble should also be u p r o o t e d o r b u r n e d t o p r e v e n t the c o n t i n u e d g r o w t h a n d s e e d i n g of the p a r a s i t e. 44
46 45
47 R o t a t i o n s C r o p r o t a t i o n o f f e r s g o o d p o t e n t i a l c o n t r o l w h e r e v e r i t i s p r a c t i c a b l e. R o t a t i o n w i t h t r a p c r o p s ( c r o p s t h a t g e r m i - n a t e Striga s e e d but a r e n o t p a r a s i t i z e d ) s u c h a s c o t t o n, s u n f l o w e r, g r o u n d n u t, a n d s o m e o t h e r l e g u m e s n o t o n l y r e d u c e s t h e Striga s e e d r e s e r v o i r i n t h e soil b u t a l s o i n c r e a s e s c e r e a l y i e l d s b e c a u s e o f b e n e f i c i a l r o t a t i o n e f f e c t s. A b r e a k i n t h e c o n t i n u o u s c u l t i v a t i o n o f s o r g h u m w i t h a t r a p c r o p, e v e n for 1 y e a r, h a s b e e n f o u n d u s e f u l i n r e d u c i n g Striga b u i l d - u p, b u t n o t v e r y e f f e c t i v e w h e n i n f e s t a t i o n i s a l r e a d y s e v e r e. N i t r o g e n f e r t i l i z e r T h e e x a c t t i m i n g a n d f o r m o f n i t r o g e n a p p l i c a t i o n a r e n o t c r i t i c a l, t h e e s s e n t i a l r e q u i r e m e n t b e i n g t h a t t h e c r o p a b s o r b s i t a n d r e s p o n d s, V e r y h i g h l e v e l s a r e n e e d e d t o s u p p r e s s Striga a l t o g e t h e r, b u t l e v e l s r e c o m - m e n d e d for Striga-free c r o p s a r e likely t o b e h i g h l y b e n e f i c i a l i n d e l a y i n g Striga e m e r g e n c e a n d r e d u c i n g t h e d a m a g e c a u s e d. A n a p p l i c a t i o n o f 2 0 % u r e a a s a d i r e c t e d s p r a y o n e m e r g e d Striga p l a n t s c a n kill t h e p l a n t s b y s c o r c h i n g a n d t h u s r e d u c e its s e e d p r o d u c t i o n. H e r b i c i d e s N o h e r b i c i d e c a n p r o v i d e a p e r f e c t s e l e c t i v e c o n t r o l o f Striga. B u t, w h e r e 2, 4-0 c a n b e s a f e l y u s e d i n t h e c e r e a l c r o p s, i t m a y a t l e a s t p a r t i a l l y p r e v e n t e m e r g e n c e w h e n a p p l i e d a t a b o u t t h e t i m e o f Striga g e r m i n a t i o n, o r i t m a y kill e m e r g e d p a r a s i t e s w h e n a p p l i e d later. O t h e r h e r b i - c i d e s s u c h a s l i n u r o n, b r o m o x y n i l, a n d a m e t r y n e h a v e b e e n s u g g e s t e d f o r d i r e c t e d s p o t - s p r a y i n g i n m i x e d c r o p s w h e r e i t w o u l d n o t b e s a f e t o u s e 2, 4 - D. 4 6
48 G e r m i n a t i o n s t i m u l a n t s E t h y l e n e g a s, a n d s o m e s y n t h e t i c a n a l o g u e s o f n a t u r a l g e r m i n a t i o n s t i m u l a n t s, c a n b e e f f e c t i v e i n t r i g g e r i n g " s u i c i d a l " g e r m i n a t i o n o f Striga s e e d i n t h e s o i l. E t h y - l e n e i s b e i n g e x t e n s i v e l y u s e d i n t h e U S A, b u t t h e t e c h - n i q u e h a s n o t y e t b e e n d e v e l o p e d for u s e e l s e w h e r e. B i o c o n t r o l P r a c t i c a l b i o c o n t r o l t e c h n i q u e s a r e y e t t o b e d e v e l o p e d, b u t p o t e n t i a l l y u s e f u l o r g a n i s m s i n c l u d e t h e f o l l o w i n g. a. T h e g a l l - f o r m i n g w e e v i l ( S m i c r o n y x umbrinus) t h a t l a y s e g g s i n t h e f l o w e r b u d s ( s e e F i g. 3 1 s h o w i n g d a m - a g e o n S. hermonthica). T h e g r u b s ( F i g. 3 2 : x 8 0 ) f e e d o n t h e o v u l e s a n d e f f e c t i v e l y r e d u c e s e e d p r o d u c t i o n, s o m e t i m e s b y %. I n S. gesnerioides, g a l l s m a y b e f o r m e d i n t h e s t e m a s w e l l. b. T h e b u t t e r f l y Precis (= Junonia) s p e c i e s w h o s e l a r v a e f e e d o n l e a v e s, b u d s, a n d c a p s u l e s o f m a n y Striga s p e c i e s ( F i g. 3 3 ). c. A r a n g e of f u n g a l d i s e a s e s, i n c l u d i n g Fusarium equiseti t h a t c a u s e s g i r d l i n g o f t h e s t e m a n d v a r y i n g d e g r e e s o f d a m a g e, i n c l u d i n g t h e a b o r t i o n o f s e e d c a p - s u l e s o r a c o m p l e t e kill o f y o u n g p l a n t s ( F i g. 3 4 ). I n t e g r a t e d c o n t r o l W h i l e a n y o f t h e a b o v e a p p r o a c h e s m a y n o t b e a d e - q u a t e o n t h e i r o w n, c o m b i n a t i o n s o f t w o o r m o r e c o n t r o l m e a s u r e s c a n m a k e a s i g n i f i c a n t i m p a c t. 4 7
49 Figure 31 48
50 Figure 32 Figure 33 49
51 Figure 34 50
52 P h o t o C r e d i t s UK W e e d R e s e a r c h O r g a n i z a t i o n (C. P a r k e r ) : 2, 3, 5, 6, 7, 9, 10, 14, 17, 19, 2 1, 2 3, 2 5, 2 6, 27, , 3 2, 3 4 K.V. R a m a i a h : 4, 13, 18, 2 2, 2 9, 3 0. M. J. V a s u d e v a R a o : 1, 8, 15, 16, 2 0, b a c k c o v e r. L.J. M u s s e l m a n : 12, 2 4, 3 3. L R. H o u s e : 1 1, front c o v e r. 51
53
New Implements for Crop Production in the Semi-Arid Tropics
New Implements for Crop Production in the Semi-Arid Tropics Information Bulletin no. 27 International Crops Research Institute for the Semi-Arid Tropics Abstract C i t a t i o n : A w a d h w a l, N.K.,
More informationRAINFALL PROBABILITY ESTIMATES FOR SELECTED LOCATIONS OF SEMI-ARID INDIA
RAINFALL PROBABILITY ESTIMATES FOR SELECTED LOCATIONS OF SEMI-ARID INDIA RESEARCH BULLETIN NO. 1 2 n d Edition - Enlarged S. M. V I R M A N I M. V. K. SIVA K U M A R A N D S. J. R E D D Y International
More informationGrowing Chickpea in Eastern Africa
Citation: I C R I S A T ( I n t e r n a t i o n a l C r o p s R e s e a r c h I n s t i t u t e f o r t h e S e m i - A r i d T r o p i c s ). 1 9 9 1. G r o w i n g c h i c k p e a i n e a s t e r n A
More informationProceedings of the. I n t e r n a t i o n a l W o r k s h o p o n I n t e r c r o p p i n g
Proceedings of the I n t e r n a t i o n a l W o r k s h o p o n I n t e r c r o p p i n g H y d e r a b a d, I n d i a 1 0-1 3 J a n u a r y 1 9 7 9 International Crops Research Institute for t h e Semi-Arid
More informationBrown planthopper: THREAT TO RICE PRODUCTION IN ASIA
Brown planthopper: THREAT TO RICE PRODUCTION IN ASIA 1979 INTERNATIONAL RICE RESEARCH INSTITUTE LOS BAÑOS, LAGUNA, PHILIPPINES P.O. BOX 933, MANILA, PHILIPPINES The International Rice Research Institute
More informationWorking Group on Medicinal and Aromatic Plants November 2011
Working Group on Medicinal and Aromatic Plants November 2011 Highly discriminating descriptors in this descriptor list are marked with an asterisk [ ]. Characterization should preferably be done during
More informationBiophysical Basis of Resistance against Shoot Bug (Peregrinus maidis) in Different Genotypes of Rabi Sorghum
International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 10 (2017) pp. 707-712 Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2017.610.087
More informationCharacterization of ICRISAT-bred restorer parents of pearl millet
Characterization of ICRISAT-bred restorer parents of pearl millet SK Gupta 1 *, Ranjana Bhattacharjee 1,2, KN Rai 1 and M Suresh Kumar 1 1. International Crops Research Institute for the Semi-Arid Tropics
More informationUnit G: Pest Management. Lesson 2: Managing Crop Diseases
Unit G: Pest Management Lesson 2: Managing Crop Diseases 1 Terms Abiotic disease Bacteria Biotic disease Cultural disease control Disease avoidance Disease resistance Disease tolerance Fungi Infectious
More informationUnit D: Controlling Pests and Diseases in the Orchard. Lesson 5: Identify and Control Diseases in the Orchard
Unit D: Controlling Pests and Diseases in the Orchard Lesson 5: Identify and Control Diseases in the Orchard 1 Terms Abiotic disease Bacteria Biotic diseases Cultural disease control Disease avoidance
More informationTECHNICAL WORKING PARTY FOR AGRICULTURAL CROPS. Twenty-Ninth Session Uppsala, Sweden, June 27 to 30, 2000
E TWA/29/17 ORIGINAL: English DATE: June 6, 2000 INTERNATIONAL UNION FOR THE PROTECTION OF NEW VARIETIES OF PLANTS GENEVA TECHNICAL WORKING PARTY FOR AGRICULTURAL CROPS Twenty-Ninth Session Uppsala, Sweden,
More informationComparison of physiological responses of pearl millet and sorghum to water stress
Proc. Indian Acad. Sci. (Plant Sci.), Vol. 99, No. 6, December 1989, pp. 517-522. (~ Printed in India. Comparison of physiological responses of pearl millet and sorghum to water stress V BALA SUBRAMANIAN
More informationEvaluation of sweet sorghum hybrid parents for resistance to grain mold, anthracnose, leaf blight and downy mildew
Evaluation of sweet sorghum hybrid parents for resistance to grain mold, anthracnose, leaf blight and downy mildew RP Thakur*, Rajan Sharma, P Srinivasa Rao, P Sanjana Reddy, VP Rao and Belum VS Reddy
More informationTitle: Plant Nitrogen Speaker: Bill Pan. online.wsu.edu
Title: Plant Nitrogen Speaker: Bill Pan online.wsu.edu Lesson 2.3 Plant Nitrogen Nitrogen distribution in the soil-plantatmosphere Chemical N forms and oxidation states Biological roles of N in plants
More informationParasitic Diseases. Plants killing plants
Parasitic Diseases Plants killing plants Parasitic Plants According to the American Heritage Dictionary a parasite is- An organism that grows, feeds, and is sheltered on or in a different organism while
More informationWeed Identification and Control. Jim Wanstall NMDA State Noxious Weed Coordinator
Weed Identification and Control Jim Wanstall NMDA State Noxious Weed Coordinator What Is A Weed? A weed is any plant that interferes with the management objectives for a particular site. An invasive weed
More informationTodd A.Steinlage, Alaska Department of Natural Resources, Division of Agriculture, Plant Materials Center
Tomato Spotted Wilt Virus in Alaska Greenhouses and Nurseries Todd A.Steinlage, Alaska Department of Natural Resources, Division of Agriculture, Plant Materials Center Tomato spotted wilt virus (TSWV)
More informationWheat Rice Corn The parts are often very small Diagnostic microscope Magnifies to 45 x Compound microscope Magnifies to 400 x
Turf and Weed Grasses Identification and Management World consumption Wheat, Corn & Rice 206 Turf Pest Control Pest Management Workshop February 19, 2013 Wheat Corn Rice Grasses are monocots 644 genera
More informationSample Worksheets For Fieldwork At. Birmingham Botanical Gardens
Sample Worksheets For Fieldwork At Introduction These sample worksheets have been designed so that you can select from them in order to create your own booklet. Differentiation can be achieved either by:
More informationEstimation of Heterosis, Heterobeltiosis and Economic Heterosis in Dual Purpose Sorghum [Sorghum bicolor (L.) Moench]
International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 6 Number 5 (2017) pp. 990-1014 Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2017.605.109
More informationExport Destinations and Input Prices. Appendix A
Export Destinations and Input Prices Paulo Bastos Joana Silva Eric Verhoogen Jan. 2016 Appendix A For Online Publication Figure A1. Real Exchange Rate, Selected Richer Export Destinations UK USA Sweden
More informationDiagnosing Plant Problems. A strategy to get started
+ Diagnosing Plant Problems A strategy to get started + Causes of plant damage Living factors Pests such as insects, mites, rodents, mammals Pathogens that cause disease such as fungi, bacteria, viruses,
More informationDo Policy-Related Shocks Affect Real Exchange Rates? An Empirical Analysis Using Sign Restrictions and a Penalty-Function Approach
ISSN 1440-771X Australia Department of Econometrics and Business Statistics http://www.buseco.monash.edu.au/depts/ebs/pubs/wpapers/ Do Policy-Related Shocks Affect Real Exchange Rates? An Empirical Analysis
More informationCalifornia Fuchsia Onagraceae Evening Primrose Family Epilobium canum
6. California Fuchsia Onagraceae Evening Primrose Family Epilobium canum California Fuchsia, also known as Hummingbird Flower, Hummingbird Trumpet, and Firechalice, is a species of willowherb that is native
More information3.3 TXT + WKBK answers.docx Page 1 of 5
3.3TXT+WKBKanswers.docx Page1of5 TEXTBOOK SECTION3.3ASSESSMENT,p.147 CheckYourUnderstandingAnswers CheckingConcepts 1.(a)Sampleanswer:Anexampleofanative speciesiswhitebarkpineintherocky MountainsorGarryoakinVancouver
More informationWeather Report 05 January 2018
Weather Report 05 January 2018 South Africa - Weather Crop conditions will remain generally favorable across eastern South Africa during the next two weeks. Net drying will gradually reduce soil moisture,
More informationSun Helps Geraniums Poison Japanese Beetles
April, 1929 71 Sun Helps Geraniums Poison Japanese Beetles An insect poison that seems to need the aid of the sun to develop its best effects has been observed in connection with the campaign against the
More informationWeather Report 31 January 2018
Weather Report 31 January 2018 South Africa - Weather The erratic rain pattern will continue on a frequent basis for the eastern half of South Africa during the coming week. Moisture totals through next
More informationCommon Name: FLORIDA ADDER S-MOUTH ORCHID. Scientific Name: Malaxis spicata Swartz. Other Commonly Used Names: none
Common Name: FLORIDA ADDER S-MOUTH ORCHID Scientific Name: Malaxis spicata Swartz Other Commonly Used Names: none Previously Used Scientific Names: Malaxis floridana (Chapman) Kuntze, Microstylis floridana
More informationParasitic plants. form follows function. Background. Parasitism occurs in at least 17 different families. 8 of which are considered weedy pests
Parasitic plants form follows function Background Parasitism occurs in at least 17 different families. 8 of which are considered weedy pests degrees of parasitism: hemi-parasite or semi-parasite holo-parasite
More informationFIELD IDENTIFICATION CARDS FOR INVASIVE NON-NATIVE PLANT SPECIES KNOWN TO THREATEN ARIZONA WILDLANDS.
FIELD IDENTIFICATION CARDS FOR INVASIVE NON-NATIVE PLANT SPECIES KNOWN TO THREATEN ARIZONA WILDLANDS. PACKET CONTAINS INFORMATION ON 74 INVASIVE NON-NATIVE PLANTS INCLUDING: morphologic descriptions photos
More informationUnit 1 Test - Version A
Unit 1 Test - Version A 1. Approximately, how many degrees of longitude equal one time zone change? a. 5 b. 10 c. 15 d. 20 e. 25 2. The city of Lewisville has a population of 1,000 people living in 100
More informationNigerian Capital Importation QUARTER THREE 2016
Nigerian Capital Importation QUARTER THREE 2016 _ November 2016 Capital Importation Data The data on Capital Importation used in this report was obtained from the Central Bank of Nigeria (CBN). The data
More informationU.S. Fish & Wildlife Service. Attracting Pollinators to Your Garden
U.S. Fish & Wildlife Service Attracting Pollinators to Your Garden Why are Pollinators Important? Pollinators are nearly as important as sunlight, soil and water to the reproductive success of over 75%
More informationPlant Crib VERONICA. 1. Veronica serpyllifolia
VERONICA 1. Veronica serpyllifolia Illustrations reproduced, with permission, from M. McC. Webster (1978). Flora of Moray, Nairn & East Inverness. Aberdeen. Subsp. humifusa (Dicks.) Syme Subsp. serpyllifolia
More informationDiseases of Sesame. Dr. S. Parthasarathy, M.Sc. (Ag)., Ph.D., FBSS.
Diseases of Sesame Dr. S. Parthasarathy, M.Sc. (Ag)., Ph.D., FBSS. Assistant Professor (Plant Pathology), Dept. of Plant Pathology, College of Agricultural Technology, Theni Diseases of Sesame Charcoal
More informationDevelopment of male-sterile lines in sorghum
Development of male-sterile lines in sorghum A Ashok Kumar, Belum VS Reddy, P Sanjana Reddy and B Ramaiah International Crops Research Institute for the Semi-Arid Tropics, Patancheru 502 324, Andhra Pradesh,
More informationSituation of corn in Myanmar
Situation of corn in Myanmar Phyu Phwe New Plant Variety Protection Unit Department of Agricultural Research(DAR) (2. 8.2016) Introduction Maize - second mandate cereal in Myanmar after rice Mainly utilized
More informationDectes Stem Borer: A Summertime Pest of Soybeans
Dectes Stem Borer: A Summertime Pest of Soybeans Veronica Johnson* and Cerruti R 2 Hooks $ University of Maryland Dept. of Entomology * Graduate student and $ Associate professor and Extension Specialist
More informationPart 1: Naming the cultivar
REGISTRATION FORM FOR a CULTIVAR NAME of POPULUS L. Sub-Committee for Nomenclature and Registration FAO - International Poplar Commission (appointed in 1958 as the ICRA for the genus Populus) Addresses
More informationAbstract Malti, R.K., and Bidinger, F.R
Abstract Malti, R.K., and Bidinger, F.R. 1981. Growth and development of the pearl millet plant. Research Research Bulletin no.6. Patancheru, A.P., India: International Crops Research Institute for the
More informationDeterioration of Crop Varieties Causes and Maintenance
Deterioration of Crop Varieties Causes and Maintenance Deterioration of Genetic Purity The genetic purity of a variety or trueness to its type deteriorates due to several factors during the production
More informationCommon Name: YELLOW LADY S-SLIPPER. Scientific Name: Cypripedium parviflorum Salisbury. Other Commonly Used Names: golden slipper
Common Name: YELLOW LADY S-SLIPPER Scientific Name: Cypripedium parviflorum Salisbury Other Commonly Used Names: golden slipper Previously Used Scientific Names: Cypripedium calceolus Linnaeus Family:
More informationGermplasm. Introduction to Plant Breeding. Germplasm 2/12/2013. Master Gardener Training. Start with a seed
Introduction to Plant Breeding Master Gardener Training Start with a seed Germplasm Germplasm The greatest service which can be rendered to any country is to add a useful plant to its culture -Thomas Jefferson
More informationIntroduction to Plant Breeding. Master Gardener Training
Introduction to Plant Breeding Master Gardener Training Start with a seed Germplasm Germplasm The greatest service which can be rendered to any country is to add a useful plant to its culture -Thomas Jefferson
More informationMonthly overview. Rainfall
Monthly overview 1 to 10 April 2018 Widespread rainfall continued to fall over most parts of the summer rainfall region during this period. Unseasonably good rain fell over the eastern half of the Northern
More informationFrequency analysis of rainfall deviation in Dharmapuri district in Tamil Nadu
Indian Journal of Geo Marine Sciences Vol.46 (8), August 217, pp. 171-1714 Frequency analysis of rainfall deviation in Dharmapuri district in Tamil Nadu V. Rajendran 1* & R. Venkatasubramani 2 1 Department
More informationPollination, the Grand Interaction Among Flowers, Bees, Growers and Beekeepers
Pollination, the Grand Interaction Among Flowers, Bees, Growers and Beekeepers EASTERN KENTUCKY BEEKEEPING SCHOOL PROGRAM, January 20, 2018 Hazard Community and Technical College John A. Skinner University
More informationPollen fertility Vs Spikelet fertility in F2 of a CMS based hybrids in rice (Oryza sativa L.) under Aerobic condition
Research Article Pollen fertility Vs Spikelet fertility in F of a CMS based hybrids in rice (Oryza sativa L.) under Aerobic condition N.Naresh Babu,N.Shivakumar and Shailaja Hittalmani Abstract : Identification
More informationIdentifying Wheat Growth Stages
AGR-224 Identifying Wheat Growth Stages Carrie A. Knott, Plant and Soil Sciences University of Kentucky College of Agriculture, Food and Environment Cooperative Extension Service Identifying growth stages
More information4/26/18. Domesticated plants vs. their wild relatives. Lettuce leaf size/shape, fewer secondary compounds
The final exam: Tuesday, May 8 at 4:05-6:05pm in Ruttan Hall B35. 75 multiple choice questions for 150 points 50 questions from Lecture 20 27 25 questions directly from the first two exams. Key for exam
More informationDetermination of Economic Threshold level (ETL) of brown planthopper, Nilaparvata lugens Stal. population in different stages of rice crop at Raipur
INTERNATIONAL JOURNAL OF PLANT PROTECTION VOLUME ISSUE APRIL, - e ISSN-- Visit us : www.researchjournal.co.in IJPP RESEARCH PAPER DOI :./HAS/IJPP/./- Determination of Economic Threshold level (ETL) of
More informationYou are encouraged to answer/comment on other people s questions. Domestication conversion of plants or animals to domestic uses
The final exam: Tuesday, May 8 at 4:05-6:05pm in Ruttan Hall B35. 75 multiple choice questions for 150 points 50 questions from Lecture 20 27 25 questions directly from the first two exams. Key for exam
More information6 2 Insects and plants
6 2 Insects and plants Insect DIY 1. Find plant habitat 2. Find plant 3. Accept plant 4. Eat survive, reproduce Plant characteristics Shape structure Mechanical defenses trichomes Chemical defenses sap,
More informationPlant Glandular Trichomes
Plant Trichomes Chemical Factories with Many Potential- Uses A John Peter and Thomas G Shanower Most plants have hairs, called trichomes, on their surface that serve a number of functions ranging from
More informationWeeds Will Be With Us So, we need to develop weed management plans.
Weeds Will Be With Us So, we need to develop weed management plans. The First Step: Weed ID Its more than a name How do you correctly identify a weed? Compare to a photo Remember weeds can appear different
More information2017 Source of Foreign Income Earned By Fund
2017 Source of Foreign Income Earned By Fund Putnam Emerging Markets Equity Fund EIN: 26-2670607 FYE: 08/31/2017 Statement Pursuant to 1.853-4: The fund is hereby electing to apply code section 853 for
More informationAppendix B: Detailed tables showing overall figures by country and measure
44 country and measure % who report that they are very happy Source: World Values Survey, 2010-2014 except United States, Pew Research Center 2012 Gender and Generations survey and Argentina 32% 32% 36%
More informationPassiflora coriacea (bat-leafed passion flower)
Australia/New Zealand Weed Risk Assessment adapted for Florida. Data used for analysis published in: Gordon, D.R., D.A. Onderdonk, A.M. Fox, R.K. Stocker, and C. Gantz. 28. Predicting Invasive Plants in
More informationORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT
ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT Pursuant to Article 1 of the Convention signed in Paris on 14th December 1960, and which came into force on 30th September 1961, the Organisation
More informationRESULTS REGARDING BIOLOGICAL CHARACTERISTICS OF THE SPECIES LALLEMANTIA IBERICA IN THE SPECIFIC CONDITIONS FROM SOUTH ROMANIA
Scientific Papers, UASVM Bucharest, Series A, Vol. LIV, 2011, ISSN 1222-5339 RESULTS REGARDING BIOLOGICAL CHARACTERISTICS OF THE SPECIES LALLEMANTIA IBERICA IN THE SPECIFIC CONDITIONS FROM SOUTH ROMANIA
More informationgrain molds 59 witchweeds 63 banded leaf & sheath blight 67 downy mildew 68 ergot 75 smut 79 rust 80 leaf blast 83 zonate leaf spot 84
CONTENTS SORGHUM sorghum downy mildew 2 crazy top downy mildew 6 leaf blight 9 sooty stripe 10 zonate leaf spot 13 rough leaf spot 14 rust 17 grey leaf spot 18 oval leaf spot 21 tar spot 22 anthracnose
More informationGENETIC RESOURCES IN AGRICULTURE
GENETIC RESOURCES IN AGRICULTURE TOPIC 1: ORIGIN and DISTRIBUTION of CROP PLANTS Centre of origin: Geographical area where a plant species, either domesticated or wild, first developed with special characteristics
More informationEuphorbia pulcherrima (poinsettia) Has the species become naturalised where grown? n Does the species have weedy races?
Australia/New Zealand Weed Risk Assessment adapted for Data used for analysis published in: Gordon, D.R., D.A. Onderdonk, A.M. Fox, R.K. Stocker, and C. Gantz. 28. Predicting Invasive Plants in Florida
More informationAgapanthus Gall Midge update (Hayley Jones, Andrew Salisbury, Ian Waghorn & Gerard Clover) all images RHS
Agapanthus Gall Midge update 20.10.2015 (Hayley Jones, Andrew Salisbury, Ian Waghorn & Gerard Clover) all images RHS Background The agapanthus gall midge is an undescribed pest affecting Agapanthus that
More informationThe impact of Agrobacterium tumefaciens and other soil borne disease causing agents of economic importance in production of roses
The impact of Agrobacterium tumefaciens and other soil borne disease causing agents of economic importance in production of roses Video conference on global competitiveness of the flower industry in the
More informationRefer to FIGURE 1 which shows how temperatures over a city and its surrounding areas differ. This is an example of microclimate.
CLIMATE & WEATHER Checklist Make sure you know how to: Describe global air circulation Explain formation and effects of tropical cyclones Identify and explain weather patterns over southern Africa Interpret
More informationKodo millet (Paspalum scorbiculatum L.)
Kodo millet (Paspalum scorbiculatum L.) I Subject: These test guidelines apply to all the varieties, hybrids and parental lines of Kodo millet (Paspalum scorbiculatum L.) II Material required: 1. The Protection
More informationThe study of Geography and the use of geographic tools help us view the world in new ways.
S How does Geography help us understand our world? What factors shape the Earth s different environments? 7.1.9 7.2.9 BIG IDEAS COMPETENCIES Text pages or The study of Geography and the use of geographic
More informationDEPARTMENT OF ANIMAL AND PLANT SCIENCES Autumn Semester ANIMAL POPULATION & COMMUNITY ECOLOGY
APS208 DEPARTMENT OF ANIMAL AND PLANT SCIENCES Autumn Semester 2006-2007 ANIMAL POPULATION & COMMUNITY ECOLOGY Your answers should include named examples, and diagrams where appropriate. Answer TWO questions.
More informationCanadian Imports of Honey
of 0409000029 - Honey, natural, in containers of a weight > 5 kg, nes (Kilogram) Argentina 236,716 663,087 2,160,216 761,990 35.27% 202.09% /0 76,819 212,038 717,834 257,569 35.88% 205.69% /0 United States
More informationCorporate Governance, and the Returns on Investment
Corporate Governance, and the Returns on Investment Klaus Gugler, Dennis C. Mueller and B. Burcin Yurtoglu University of Vienna, Department of Economics BWZ, Bruennerstr. 72, A-1210, Vienna 1 Considerable
More informationWeed Competition and Interference
Weed Competition and Interference Definition two organisms need essential materials for growth and the one best suited for the environment will succeed (humans usually manipulate so that crops succeed)
More informationDescriptions and Performance
LSU AgCenter Coastal Plants Program Smooth Cordgrass Varieties: Descriptions and Performance Smooth cordgrass (Spartina alterniflora Loisel.) is a perennial grass native to intertidal saline marshes along
More informationLassen Community College Course Outline
Lassen Community College Course Outline AGR 20 Introduction to Plant Science 4.0 Units I. Catalog Description This course is an introduction to plant science including structure, growth processes, propagation,
More informationBiomes There are 2 types: Terrestrial Biomes (on land) Aquatic Biomes (in the water)
Biomes There are 2 types: Terrestrial Biomes (on land) Aquatic Biomes (in the water) Terrestrial Biomes Grassland, Desert, and Tundra Biomes: Savanna Temperate grassland Chaparral Desert Tundra Chapter
More informationSite Specific Management Center Newsletter, Purdue University, April,
Using Spectral Vegetation Indices to Differentiate Weeds and Mint in Remote Sensing Images Mary Gumz and Stephen C. Weller Department of Horticulture and Landscape Architecture Introduction Remote sensing-based
More informationUNIT 3. PLANTS. PRIMARY 4/ Natural Science Pedro Antonio López Hernández
UNIT 3. PLANTS PRIMARY 4/ Natural Science Pedro Antonio López Hernández They help to keep it in place. Roots They take in the water and minerals a plant needs to make its food. They support the leaves.
More informationSAMPLING IN FIELD EXPERIMENTS
SAMPLING IN FIELD EXPERIMENTS Rajender Parsad I.A.S.R.I., Library Avenue, New Delhi-0 0 rajender@iasri.res.in In field experiments, the plot size for experimentation is selected for achieving a prescribed
More informationPrentice Hall. World Explorer: People, Places, Cultures Grade 7. Oklahoma Priority Academic Student Skills (PASS) for Grade 7 World Geography
Prentice Hall World Explorer: People, Places, Cultures 2007 Grade 7 C O R R E L A T E D T O for Grade 7 1. Locate, gather, analyze, and apply information from primary and secondary sources. WORLD GEOGRAPHY
More informationWorking Group on Medicinal and Aromatic Plants November 2011
Working Group on Medicinal and Aromatic Plants November 2011 Draft Descriptor List Carum spp. Highly discriminating descriptors in this descriptor list are marked with an asterisk [ ]. Characterization
More informationSEASONAL CLIMATE OUTLOOK VALID FOR JULY-AUGUST- SEPTEMBER 2013 IN WEST AFRICA, CHAD AND CAMEROON
SEASONAL CLIMATE OUTLOOK VALID FOR JULY-AUGUST- SEPTEMBER 2013 IN WEST AFRICA, CHAD AND CAMEROON May 29, 2013 ABUJA-Federal Republic of Nigeria 1 EXECUTIVE SUMMARY Given the current Sea Surface and sub-surface
More informationGLYPHOSATE, IMAZAPYR AND?? HERBICIDES FOR GRASS CONTROL - Greg MacDonald Agronomy Dept. University of Florida
GLYPHOSATE, IMAZAPYR AND?? HERBICIDES FOR GRASS CONTROL - Greg MacDonald Agronomy Dept. University of Florida TYPES OF GRASSES Perennial or Annual Bunch or Spreading Stolons or Rhizomes Viable Seeds or
More informationLaboratory III Quantitative Genetics
Laboratory III Quantitative Genetics Genetics Biology 303 Spring 2007 Dr. Wadsworth Introduction Mendel's experimental approach depended on the fact that he chose phenotypes that varied in simple and discrete
More informationBy the end of this lesson, you should be able to
Allelopathy 1 Allelopathy By the end of this lesson, you should be able to define allelopathy explain the difference between allelopathy and competition identify the key interactions in allelopathy provide
More informationSCREENING OF CARNATION VARIETIES AGAINST THRIPS, Thrips tabaci (LINDERMAN) IN PROTECTED CULTIVATION
e- ISSN: 2394-5532 p- ISSN: 2394-823X General Impact Factor (GIF): 0.875 International Journal of Applied And Pure Science and Agriculture www.ijapsa.com SCREENING OF CARNATION VARIETIES AGAINST THRIPS,
More informationBonza Botanicals Pty., Ltd., Yellow Rock, New South Wales, Australia Agent in Canada: BioFlora Inc., St. Thomas, Ontario Breeder:
(Xerochrysum bracteatum) Proposed denomination: Bondre 1051 Trade name: Dreamtime Jumbo Rose Application number: 14-8476 Application date: 2014/11/13 Applicant: Bonza Botanicals Pty., Ltd., Yellow Rock,
More informationCommon Name: GLADE WINDFLOWER. Scientific Name: Anemone berlandieri Pritzel. Other Commonly Used Names: southern thimble-weed
Common Name: GLADE WINDFLOWER Scientific Name: Anemone berlandieri Pritzel Other Commonly Used Names: southern thimble-weed Previously Used Scientific Names: Anemone caroliniana Walter var. heterophylla
More informationTopics. Physiological Disorders and Environmental Stresses. Physiological Disorders. Physiological Disorders
Topics Physiological Disorders and Environmental Stresses Kimberly Williams Overview and terminology Caused by chemicals or air pollution Caused by moisture management Caused by temperature and/or light
More informationBiology and management of dodder a new threat to the canola industry
Biology and management of dodder a new threat to the canola industry Abul Hashem Department of Agriculture and Food Western Australia Centre for Cropping Systems P.O. Box 483, Northam WA 641, Australia
More informationSeed production potential of ICRISAT-bred parental lines of two sorghum hybrids in the central Rift-valley of Ethiopia
Seed production potential of ICRISAT-bred parental lines of two sorghum hybrids in the central Rift-valley of Ethiopia Asfaw Adugna* and Tesfaye Tesso Melkassa Agricultural Research Center, PO Box 436,
More informationVerwijsnummer rapporterende autoriteit: MDN 5 Reference number reporting authority: MDN 5
Medinilla Gaudich. Variety description: NL/MDN/1 1. Reference number of reporting authority Reference number of requesting 2. authority 3. Breeder s reference Medin-8295 4. Applicant Corn.Bak, ASSENDELFT,
More informationPhysical Geography. Ariel view of the Amazon Rainforest. A Look at the Seven Continents
Physical Geography In this unit you will learn about general physical geography. The study of the Earth s surface features provides the setting for the human-environmental interactions and for the human
More informationUnderstanding the genetic control of flowering time to create adapted and high yielding narrow-leafed lupins
Understanding the genetic control of flowering time to create adapted and high yielding narrow-leafed lupins Candy Taylor UWA School of Agriculture and Environment Acknowledgements Supervisors Prof Wallace
More informationIntroduction to Crucifers (Brassicaceae)
Oilseed rape (Brassica napus) Introduction to Crucifers (Brassicaceae) Tim Rich Brassicaceae (Cruciferae) - Crucifers c. 3500 species in 350 genera Lots of recent taxonomic changes in genera from DNA Found
More informationAllium vineale (Wild garlic )
1 of 5 9/24/2007 3:40 PM Home Early Detection IPANE Species Data & Maps Volunteers About the Project Related Information Catalog of Species Search Results :: Catalog of Species Search Allium vineale (Wild
More informationWeather Report 29 November 2017
Weather Report 29 November 2017 South Africa - Weather The erratic rain pattern will continue for portions of eastern and central India during the coming week. Moisture totals through next Tuesday morning
More informationGrowth Stages of Wheat: Identification and Understanding Improve Crop Management
Growth Stages of Wheat: Identification and Understanding Improve Crop Management B y Travis D. Miller Understanding growth stages of wheat is important in matching management decisions and inputs with
More informationWorld Agricultural Outlook Board Interagency Commodity Estimates Committee Forecasts. Lockup Briefing April 10, 2013
World Agricultural Outlook Board Interagency Commodity Estimates Committee Forecasts Lockup Briefing World Wheat Production Country or Region estimate 2012/13 previous month Million Tons Percent Percent
More informationMicrobial DNA qpcr Multi-Assay Kit Clostridium perfringens Pathogenicity
Microbial DNA qpcr Multi-Assay Kit Clostridium perfringens Pathogenicity Cat. no. 330043 BBID-1507ZR-3 For real-time PCR-based, application-specific microbial identification or profiling The Clostridium
More information