SACCHARIMETER )
H. Koike USDA, ARS
B e l t s v i l l e , Maryland
H. Koike USDA, ARS Houma, L o u i s i a n a
ABSTRACT
The number of diagnostic bacteria present in crude juice of various ratoon stunting disease (RSD)- Infected sugarcane clones was determined by phase contrast microscopy. Sugarcane clones (CP 29-116, CP 52-68 and L 60-25) resistant to RSD injury, and clones (CP 36-105, CP 53-1, L 62-96 and L 65-69) susceptible to RSD injury, were grown from RSD-infected cuttings in the field at Houma, Louisiana.
Three stalks of each clone were harvested in June, September, October and November, 1975. The stalks were milled separately, and various dilutions of the crude juice were assayed for infectivity on sugarcane clone CP 44-101. Diagnostic bacteria were counted in 10 microscope fields for each of two drops from every undiluted juice sample. Generally, the bacterial counts and the dilution end points of infectivity were directly related. Juice from clones resistant to RSD injury contained fewer diagnostic bacteria than did juice from susceptible clones. Thus, phase contrast microscopy may have potential as an improved method for screening sugarcane for resistance to RSD injury. The method is rapid and yields bacterial counts which correlate with clones resistant or susceptible to RSD injury.
101
ROGUING SUGARCANE MOSAIC US ING GLYPHOSATE (ROUNDUP) Hugh P. Fanguy and Donnie D. G a r r i s o n
U . S . Sugarcane F i e l d Laboratory Houma, L o u i s i a n a
ABSTRACT
Most of the Louisiana sugarcane crop is infected with the sugarcane mosaic virus. Growers are able to dig out mosaic-infected plants from seed plots where low levels of infection exist. It is very important that the most effective and economical method of roguing is available to growers who wish to continue this practice. Glyphosate was tested for chemical roguing of mosaic-infested plants in a field of CP 65-357 with 7.9% mosaic. Roundup (containing 41% glyphosate) was used at two rates, i.e., 3.3 and 6.7 cc per liter of water using a backpack sprayer on June 23, 1975. Both rates effectively stopped growth and killed all but a few terminal and lateral buds. The mosaic- infected plants were either dead or badly stunted when observed on September 9, 1975. The drift of glyphosate applied by the backpack sprayer killed neighboring healthy plants. Alternative methods of applying glyphosate to reduce drift will be discussed.
102
AERATED STEAM--ANOTHER METHOD OF CONTROLLING RATOON STUNTING DISEASE OF SUGARCANE R. J. Steib, 0. M. Cifuentes, B. J. Cochran, and M. M. Mayeux
Louisiana Agricultural Experiment Station Baton Rouge, Louisiana
ABSTRACT
Aerated steam (AS), a mixture of air and steam, showed promise in 1974 as a new method of controll- ing the ratoon stunting disease (RSD). Further studies indicated the hot-air (HA) oven now used in Louisiana could be converted to AS. Good germination and RSD control seemed possible from 1974 studies.
The aims of the studies being reported were to find the best AS tenperature-time combination for best germination and RSD control (cane treated with adhering trash), as well as variety tolerance and effects of pre-treatment storage on germination. In 1974, AS at 49 C-four hours, gave limited RSD control and 50 C-four hours was found to be much more effective, with excellent germination. From greenhouse studies in 1975, using cane with trash for treatment with AS, 50 C-four hours gave 97.0% control of RSD, an average for six varieties. Juvenile and mature node symptoms were used to identify RSD in four-month-old plants grown in the greenhouse. Cane with trash was also treated with AS at 51 C-four hours in an oven one-third larger than the commercial HA oven. In one large greenhouse test, germina- tion and RSD control in CP 44-101, L 62-96 and CP 65-357 were both excellent. Thermocouple checks at 14 points in the large oven reached equilibrium in one hour. The same larger commercial oven was used for six weeks in the process of treating four varieties at 51 C-four hours (cane with trash) in the fall of 1975. Fall and spring germination was excellent. Preliminary tests over two years showed it may be possible to use a higher temperature with a reduced treatment period. A delay period before treating with AS after cutting was found less injurious than HA. Results of experimental and commercial- scale tests over two years indicate AS may be used to control RSD. Due to the many advantages of AS over HA, it is being made available to the Louisiana industry in 1976 as an additional method of RSD control besides the HA and hot-water treatments now being used.
103
A COMPARISON OF THE SEXUAL ATTRACTIVENESS, FERTILITY, AND FECUNDITY OF LABORATORY-REARED AND WILD ADULT SUGARCANE
BORERS1/
James W. S a n f o r d U . S . S u g a r c a n e F i e l d L a b o r a t o r y
S o u t h e r n R e g i o n , ARS, USDA Houma, L o u i s i a n a 70361
ABSTRACT
T r a p s b a i t e d w i t h l a b o r a t o r y - r e a r e d f e m a l e s u g a r c a n e b o r e r m o t h s , D i a t r a e a s a c c h a r a l i s ( F . ) , c a p t u r e d s l i g h t l y more w i l d m a l e s t h a n t r a p s b a i t e d w i t h w i l d f e m a l e s . The f e r t i l i t y and f e c u n d i t y o f l a b o r a t o r y - r e a r e d and w i l d f e m a l e s d i d n o t d i f f e r , b u t w i l d m a l e s w e r e more f e r t i l e t h a n l a b o r a t o r y - r e a r e d m a l e s .
INTRODUCTION
M a s s - r e a r e d s t e r i l e i n s e c t s a r e p r e s e n t l y b e i n g r e l e a s e d t o c o n t r o l t h e screwworm, C o c h l i o m y i a h o m i n i v o r a x ( C o q u e r e l ) , i n t h e s o u t h w e s t e r n U . S . , t o p r e v e n t t h e Mexican f r u i t f l y , A n a s t r e p h a l u d e n s
(Lowe), from e n t e r i n g C a l i f o r n i a from M e x i c o , and t o p r e v e n t t h e s p r e a d o f t h e p i n k b o l l w o r m , P e c t i n o p h o r a g o s s y p i e l l a ( S a u n d e r s ) , t o u n i n f e s t e d c o t t o n - p r o d u c i n g a r e a s i n t h e U n i t e d S t a t e s . Mass- r e a r e d i n s e c t s a r e a l s o used t o a r t i f i c i a l l y i n f e s t p l a n t s i n h o s t p l a n t r e s i s t a n c e s t u d i e s and i n a number o f p i l o t t e s t s o f g e n e t i c and b i o l o g i c a l c o n t r o l ( 3 ) . I n some o f t h e s e p r o g r a m s , t h e b e h a v i o r o f t h e m a s s - r e a r e d i n s e c t s h a s become u n s a t i s f a c t o r y , a d e v e l o p m e n t u s u a l l y a t t r i b u t e d l a r g e l y t o a d a p t i v e h e r e d i t a r y changes d u r i n g many g e n e r a t i o n s o f l a b o r a t o r y c o l o n i z a t i o n . However, t h e s u c c e s s o f p e s t management programs o f t e n depends o n t h e a d e q u a t e f i e l d p e r f o r m a n c e o f m a s s - r e a r e d r e l e a s e d i n s e c t s . I t i s t h e r e f o r e i m p o r t a n t t o i d e n t i f y and c o r r e c t any d e f i c i e n c i e s p r e s e n t i n t h e l a b o r a t o r y c o l o n i e s .
A t t h e S u g a r c a n e F i e l d L a b o r a t o r y , t h e s u g a r c a n e b o r e r , D i a t r a e a s a c c h a r a l i s ( F . ) , i s r e a r e d f o r use i n t e s t s o f i n h e r i t e d s t e r i l i t y , b i o l o g i c a l c o n t r o l , and h o s t p l a n t r e s i s t a n c e . I n view o f t h e i m p o r t a n c e o f t h e s e l a b o r a t o r y - r e a r e d i n s e c t s t o t h e r e s e a r c h e f f o r t , I r e c e n t l y b e g a n a program t o m e a s u r e and e v a l u a t e t h e p e r f o r m a n c e o f l a b o r a t o r y - r e a r e d s u g a r c a n e b o r e r s b y comparing them w i t h n o n - l a b o r a t o r y r e a r e d ( h e r e a f t e r r e f e r r e d t o a s w i l d ) s u g a r c a n e b o r e r s . The work r e p o r t e d h e r e was u n d e r - t a k e n i n a n e f f o r t t o compare t h e a t t r a c t i v e n e s s , f e r t i l i t y , and f e c u n d i t y o f l a b o r a t o r y - r e a r e d and w i l d s u g a r c a n e b o r e r f e m a l e s .
MATERIALS AND METHODS
The l a b o r a t o r y i n s e c t s used i n t h e t e s t w e r e t a k e n from a c o l o n y m a i n t a i n e d i n t h e l a b o r a t o r y f o r 7 g e n e r a t i o n s , c a . 8 m o n t h s . T h i s c o l o n y was s t a r t e d from l a r v a e c o l l e c t e d i n t h e f i e l d i n t h e T e r r e b o n n e P a r i s h a r e a o f L o u i s i a n a . The t e s t l a r v a e w e r e r e a r e d i n i n d i v i d u a l 1-oz p l a s t i c j e l l y cups o n t h e d i e t o f Burton ( 1 ) , which had been m o d i f i e d b y s u b s t i t u t i n g d r i e d g r o u n d - u p s u g a r c a n e l e a v e s f o r o n e - h a l f t h e p i n t o beans i n t h e d i e t , and were h e l d a t 2 7 + 2 C and a b o u t 80% RH, i n c o n t i n u o u s l i g h t . Pupae were sexed and h e l d at 26 C in a 14-h l i g h t : 1 0 - h d a r k p h o t o p e r i o d . Males and f e m a l e s were h e l d in s e p a r a t e c a g e s a t t h e same p h o t o p e r i o d t o i n s u r e t h a t o n l y v i r g i n f e m a l e s and unmated m a l e s w e r e used i n t h e t e s t s .
The w i l d i n s e c t s used i n t h e t e s t w e r e c o l l e c t e d a s pupae o r l a t e - i n s t a r l a r v a e from 4 l o c a t i o n s i n T e r r e b o n n e P a r i s h . Each l a r v a was p l a c e d i n a 1-oz j e l l y cup o f a r t i f i c i a l d i e t and a l l o w e d t o com- p l e t e d e v e l o p m e n t . The pupae were s e x e d , p l a c e d i n s e p a r a t e c a g e s , and were h e l d a t c o n d i t i o n s s i m i l a r t o t h o s e p r o v i d e d f o r t h e l a b o r a t o r y - r e a r e d l a r v a e and pupae a s w e r e t h e e m e r g i n g a d u l t s .
The f i r s t t e s t was made i n a f i e l d o f C P 65-357 f i r s t - s t u b b l e s u g a r c a n e a t t h e Houma s t a t i o n t o compare t h e a t t r a c t i o n o f females from t h e 2 s o u r c e s . Twelve s e x a t t r a c t a n t t r a p s ( 3 . 8 - l i t e r p a p e r c a r t o n s w i t h b o t h ends removed and t h e i n t e r i o r c o a t e d w i t h Stikem S p e c i a l ) were hung from s u g a r c a n e p l a n t s w i t h a p i e c e o f s t r i n g . F i v e were b a i t e d w i t h l a b o r a t o r y - r e a r e d f e m a l e s , 5 w e r e b a i t e d w i t h w i l d f e m a l e s , and 2 w e r e u n b a i t e d . The b a i t was a s i n g l e v i r g i n female l e s s t h a n 24 h o l d p l a c e d in a 8 x 4-cm w i r e c a g e ; 1 such c a g e was s u s p e n d e d from a w i r e hook i n t h e t o p o f e a c h t r a p . The f i r s t p a r t o f t h e s t u d y was c o n d u c t e d June 5-Aug. 1 5 and t h e s e c o n d p a r t Aug. 1 6 - S e p t . 2 4 . I n t h e f i r s t t r i a l , t h e t r a p s were p l a c e d i n t h e f i e l d i n a c o m p l e t e l y r a n d o m i z e d b l o c k d e s i g n w i t h 1 5 m between t r a p s ; t h e n t h e t r a p s were r e - r a n d o m i z e d e v e r y o t h e r d a y . I n t h e s e c o n d t r i a l , t h e t r a p s w e r e a r r a n g e d i n p a i r s , one o f which c o n t a i n e d a l a b o r a t o r y - r e a r e d female and t h e o t h e r a w i l d f e m a l e ; one t r a p of a p a i r was p l a c e d on a
1/ Research at this location is done in cooperation with the Louisiana Agricultural Experiment Station.
sugarcane plant in one row, and the other was placed directly across from it, about 1 m away, on a plant in the adjacent row. The traps were arranged in a straight line down the 2 rows with 15 m between each pair. The position of the 2 traps in each pair was alternated daily.
In both trials, the traps were checked daily, and the catch of males from the previous night was removed. Females were replaced every other day unless one died sooner, which seldom occurred; at the same time as needed, traps were replaced or recoated with Stikem Special. The data from the 2 trials were analyzed separately by a combined analysis of variance.
The second test was made in the laboratory to determine the fertility and fecundity of laboratory reared (L) and wild (W) sugarcane borers. Four series of crosses were arranged: Ld*x l4, Wd1 x I#, Lc?x W°_, and Wo* x W°-. One unmated male less than 24 h old was placed with a virgin female of like age in a 1-pt cardboard carton with a compression seal plastic lid. A piece of moist cotton placed in each carton maintained high humidity and provided water for the moths. The cartons were held in a 14-h light:
10-h dark photoperiod at 27 - 2 C. Eggs were deposited on the inner surface of the carton and lid. When the eggs in the carton began to hatch, any moths that were still alive were removed and placed in separate cartons to complete oviposition. At death all female moths were dissected, and the bursa copulatrix was examined to determine the number of spermatophores present. Fecundity was determined from the eggs laid by each female and fertility from the percentage of eggs that hatched.
RESULTS
Female a t t r a c t i v e n e s s . I n t h e f i r s t t r i a l o f female a t t r a c t i v e n e s s , t h e t r a p s b a i t e d w i t h l a b o r a - t o r y - r e a r e d f e m a l e s c a u g h t 416 m a l e s , w h i l e t h e t r a p s b a i t e d w i t h w i l d f e m a l e s c a u g h t 371 m a l e s . I n t h e s e c o n d t r i a l , t h e t r a p s b a i t e d w i t h l a b o r a t o r y f e m a l e s c a u g h t 282 m a l e s w h i l e t h e t r a p s b a i t e d w i t h w i l d f e m a l e s c a u g h t 252 m a l e s . The a n a l y s i s showed n o s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e number o f m a l e s a t t r a c t e d b y l a b o r a t o r y - r e a r e d and w i l d f e m a l e s i n e i t h e r t r i a l .
F e r t i l i t y and f e c u n d i t y . Data from t h e t e s t o f f e r t i l i t y and f e c u n d i t y a r e shown i n T a b l e 1 . Wild m a l e s e f f e c t e d a s i g n i f i c a n t l y h i g h e r p e r c e n t a g e egg h a t c h t h a n l a b o r a t o r y m a l e s , t h a t i s , t h e Wcf'x L^.
and Wd"x W°- c r o s s e s b o t h h a d h i g h e r a v e r a g e p e r c e n t a g e egg h a t c h t h a n d i d t h e Lo*x L^. and L<?x W°- c r o s s e s . T h e r e was n o s i g n i f i c a n t d i f f e r e n c e i n f e c u n d i t y among t h e f e m a l e s i n any o f t h e 4 p a i r i n g s , a n d t h e r e was n o s i g n i f i c a n t d i f f e r e n c e i n t h e number o f s p e r m a t o p h o r e s p e r f e m a l e .
a / A n a l y s i s c o n d u c t e d o n a r c s i n t r a n s f o r m a t i o n o f p e r c e n t a g e egg h a t c h ; r e t r a n s f o r m e d f i g u r e s g i v e n . Means f o l l o w e d b y t h e same l e t t e r a r e n o t s i g n i f i c a n t l y d i f f e r e n t a t t h e 5 % l e v e l b y D u n c a n ' s m u l t i p l e r a n g e t e s t .
DISCUSSION
P e r e z and Long (4) w e r e t h e f i r s t t o d e m o n s t r a t e t h e p r e s e n c e o f a c h e m i c a l s e x a t t r a c t a n t i n t h e f e m a l e s u g a r c a n e b o r e r ( 4 ) : t h e y found t h a t t h e m o t h s w e r e most a t t r a c t i v e d u r i n g t h e f i r s t 3 days o f l i f e . Sower e t a l . (6) , w o r k i n g w i t h t h e almond m o t h , C a d r a c a u t e l l a ( W a l k e r ) , found n o s i g n i f i c a n t d i f f e r e n c e s b e t w e e n t h e o u t p u t o f pheromone b y W and L f e m a l e s o r b e t w e e n t h e r e s p o n s i v e n e s s o f w i l d o r l a b o r a t o r y - r e a r e d m a l e s t o W and L f e m a l e s . R i c h e r s o n and Cameron ( 5 ) r e p o r t e d t h a t w i l d f e m a l e g y p s y m o t h s , L y m a n t r i a ( = P o r t h e t r i a ) d i s p a r ( L . ) , w e r e more a t t r a c t i v e t o w i l d m a l e s t h a n l a b o r a t o r y - r e a r e d f e m a l e s and c o n c l u d e d t h a t r e a r i n g t h e g y p s y moth o n a r t i f i c i a l d i e t a n d / o r t h e r e a r i n g c o n d i t i o n s may h a v e c a u s e d t h e r e d u c e d o u t p u t o f pheromone b y l a b o r a t o r y - r e a r e d f e m a l e s . F l i n t e t a l . ( 2 ) found n o d i f f e r e n c e b e t w e e n t h e a t t r a c t i v e n e s s o f m a s s - r e a r e d and f i e l d - c o l l e c t e d f e m a l e p i n k b o l l w o r m s , P e c t i n o p h o r a g o s s y p l e l l a ( S a u n d e r s ) . M y r e s u l t s a l s o i n d i c a t e t h a t t h e r e i s n o d i f f e r e n c e b e t w e e n t h e a t t r a c t i v e n e s s o f w i l d a n d l a b o r a t o r y - r e a r e d s u g a r c a n e b o r e r f e m a l e s .
1 0 5
The cause of the reduced f e r t i l i t y of our laboratory-reared males is unknown. It may result from a dietary deficiency or from less than optimum rearing conditions.
In sum, I found no difference among females in the sexual attractiveness or fecundity between laboratory-reared and wild populations, but laboratory-reared males were less f e r t i l e than wild males,
REFERENCES
1. Burton, R. L. 1969. Mass rearing the corn earworm in the laboratory. USDA, ARS (Ser.) 33-134.
2. Flint, H. M., R. T. Staten, L. A. Bariola, and D. L. Palmer. 1973. Gamma-irradiated pink bollworms:
attractiveness, mating, and longevity of females. Environ. Entomol. 2:97-100.
3. Klassen, W. 1974. Workshop on genetics of insect behavior. Gainesville, Florida.
4. Perez, R., and W. H. Long. 1964. Sex attractant and mating behavior in the sugarcane borer. J. Econ.
Entomol. 57:688-690.
5. Richerson, J. V., and E. A. Cameron. 1974. Differences in pheromone release and sexual behavior between laboratory-reared and wild gypsy moth adults. Environ. Entomol. 3:475-481.
6. Sower, L. L. , D. W. Hagstrum, and J. S. Long. 1973. Comparison of the female pheromones of a wild and a laboratory strain of Cadra cautella, and the male responsiveness to the pheromone extracts.
Ann. Entomol. Soc. Am. 66:484.
PRE- AND POSTEMERGENCE HERBICIDES IN LOUISIANA SUGARCANE E r n e s t R. Stamper
L o u i s i a n a A g r i c u l t u r a l Experiment S t a t i o n Baton Rouge, L o u i s i a n a
ABSTRACT
The weed and grass control recommendations of herbicides for 1976 include eight preemergence chemicals, three pre- and postemergence, and one postemergence for use in Louisiana sugarcane. Only four of the preemergence chemicals are generally used; the other four chemicals are used in specific areas in the sugarcane belt. The pre- and postemergence herbicides are generally used throughout the Louisiana sugarcane industry but have little or no use in other sugarcane growing areas of the world.
Dalapon is the only postemergence herbicide mentioned in the 1976 general recommendations however, Asulox is suggested for use in a supplemental recommendation prepared after the general recommendations were written.
Louisiana sugarcane growers may select from eight preemergence chemicals for controlling weeds and grasses in their crop. These chemicals are, Karmex, Princep, Treflan, Cotoran, Fenac, Sinbar, AAtrex, and silvex: however, only four are generally used and some are used for specific weed or grass control.
Fenac, Sinbar, Treflan, and silvex are used more than the others mentioned. Treflan is used for the control of itchgrass and to some extent in the cotton growing areas on sugarcane. These preemergence chemicals are used mostly on plant sugarcane but may, under some conditions, be used on stubble sugarcane.
Karmex, Princep, AAtrex, and Cotoran are very weak in controlling johnsongrass seedlings and are not generally used where johnsongrass seedlings are known to exist.
Three new chemical herbicide candidates have been tested and evaluated in the past several years.
These three candidates are, Chemagro's Sencor, Elanco's Spike, and Dupont's Velpar. All three of these chemicals are in the process of being registered and labeled for use in sugarcane.
The comparative effects of these materials on grass control and the yield of sugarcane are shown in Tables 1, 2, 3, 4. Tables 1 and 2 show the results when the chemicals were used on two varieties of plant sugarcane. Many combinations of chemicals and changing treatments in spring from the fall are shown in Tables 1 and 2. This shifting has been evaluated to attempt to have data in case some grass or broadleaf weed should become resistant or immune to the use of a single chemical.
Table 1. The comparative effect of several preemergence herbicides used at different rates and combina- tions on grass control and the yield of plant sugarcane 1974-75, variety CP 48-103 at Alma , Plantation.
Treatment and Fall 1974 Untreated check.1/
Sencor 1 1/2 lb-
Fenac 4 qt &
Silvex 1 lb Sencor 1 1/2 lb Sinbar 2/3 lb Spike 3/4 lb Velpar 1/4 lb Sinbar 2/3 lb Sinbar 2/3 lb
- - - -
Spike 3/4 lb
- -
rate/acre Spring
1975 Check Fenac 2 qt &
Sinbar 1/2 lb
Repeat Sinbar 2/3 Fenac 4 qt &
Silvex 1 lb Sinbar 2/3 lb Repeat Repeat Sinbar 1/2 lb &
Fenac 2 qt Velpar 1 lb Spike 3/4 lb Repeat Velpar 1/2 lb
Tons cane/acre
10.8 36.0
33.3 33.1 33.7 31.3 32.5 33.7 31.4 31.5 30.0 32.2 27.9
normal juice 14.97 15.30
14.82 14.66 14.67 15.16 14.48 13.93 14.70 14.34 14.67 13.74 14.79
Lb sugar/ton
cane 215.8 221.3
214.1 210.5 210.7 219.0 207.5 198.2 211.2 205.2 210.7 194.9 212.7
Lb sugar/acre
2331 7967
7130 7117 7100 6855 6744 6679 6632 6464 6321 6276 5934 (Continued)
% of control
-
93.0
84.0 87.0 95.0 73.0 95.0 95.0 86.0 97.0 97.0 90.0 89.0
107
Table 1. Continued
Treatment and r a t e / a c r e % s u c r o s e Lb F a l l
1974 Fenac 4 qt &
S i l v e x 1 lb Velpar 1/2 lb &
Fenac 2 qt