Deltapine Smooth Leaf Research Articles

Effects of IAA, Kinetin, and Trifluralin on Cotton Seedlings

Trifluralin (α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine), IAA (indoleacetic acid), kinetin (6-furfurylamino purine), and their combinations in culture solutions did not affect cotton (Gossypium hirsutumL., var. Deltapine Smooth Leaf) germination but reduced primary root and shoot lengths of seedlings. Trifluralin alone and in combination with IAA or kinetin inhibited lateral root development. When IAA and kinetin were both applied with 5 ppmw trifluralin, lateral roots developed.

Varietal resistance to Verticillium wilt of cotton in Queensland

Varietal differences in susceptibility (as assessed by the proportion of affected plants) to wilt of cotton caused by Verticillium dahliae Kleb., were observed in south-eastern Queensland. The progression of the disease within individual plants, however, was similar in all varieties. Deltapine Smoothleaf, the most widely grown variety in Queensland was one of the most susceptible varieties. Derivatives of Rex or Dixie King were less affected. The disease caused a difference in yield between healthy and diseased plants which could be as high as 30 per cent.

Hampea sp.,1 Host of the Boll Weevil.2 I. Laboratory Preference Studies3,4

The attraction, feeding, and oviposition of Anthonamus grandis Boheman on the dioecious plant Hampea sp., was compared with Deltapine Smoothleaf cotton by laboratory bioassay. Plant parts and extracts of the male plant were comparable to cotton in attractiveness and stimulation of feeding, but extracts of female buds and capsules were significantly less attractive than extracts of male buds and cotton buds. A volatile repellent(s) in the extracts of the female buds and capsules probably masked the attractive material(s) present, but after storage at 5°C these extracts became as attractive as extracts of the male plant and of cotton freshly prepared from buds stored at −90°C. Also, female buds contained significantly less feeding stimulant than male buds and cotton buds. This lesser concentration plus the volatile repellent produced a high degree of resistance of the boll weevil (nonpreference) to female buds and capsules.

Influence of Changes in the Cotton Plant During the Season on the Feeding, Oviposition, and Development of the Boll Weevil1234

Two varieties of cotton ( Gossypium hirsutum L.), Deltapine Smooth Leaf (DPSL) and Acala 4-42-77, were studied 2 years to determine whether changes in the plant during the growing season might affect feeding, oviposition, and development of the boll weevil, Anthonomus grandis Boheman. The criteria used to measure the effects were the tests for antibiosis, feeding stimulant, and oviposition normally used to study host-plant resistance. The overall averaged results for 2 seasons showed no differences between varieties, but there were significant differences within test periods. This interaction between variety × test period indicated that testing is necessary through several periods of a season to determine true differences among varieties. In the test of feeding stimulants, the difference between squares collected at different dates was significant only after August 24, probably because there was less feeding on samples collected August 31 and September 7; the difference between varieties was not significant. In the studies of antibiosis made with lyophilized square powder diets there were no significant differences in time to eclosion of adults and weight of emerging weevils for samples collected weekly; thus, the time of the season that squares are collected should not affect results of a test of antibiosis.

A Boll Weevil Oviposition Suppression Factor in Cotton1

The rate of boll weevil, Anthonomus grandis Boheman, oviposition was tested on 252 cotton lines, Gossypium hirsutum L. and G. barbadense L., in a nonreplicated mass screening procedure. Boll weevil oviposition was reduced in 26 lines. Replicated tests were performed on six of these by using the A & M laboratory strain and a Mississippi field strain of weevils. The two strains ranked the six cotton lines in relatively the same order. We obtained F1 hybrids of each of the 26 lines by crossing them with ‘Deltapine Smooth Leaf’ (DPSL) and tested the hybrids for oviposition with the A & M strain in replicated tests. Significant differences were found. Oviposition values ranged from 49 to 178% of the commercial DPSL parental line. ‘S. I. Seaberry’ produced the lowest oviposition rate. Inheritance studies with S. I. Seaberry ✕ DPSL were conducted in the F1, F2, and backcross progeny. Difficulty was experienced in testing individual F2 backcross plants since the test required many squares. We did, however, determine that the ability of S. I. Seaberry to suppress boll weevil oviposition was under genetic control.

Constituents of the Cotton Bud. XIII. Further Studies on a Nonpolar Feeding Stimulant for the Boll Weevil123

The nonpolar feeding stimulant complex for Anthonomus Grandis Boheman found in the buds of cotton, Gossypium hirsutum L. (Deltapine Smooth Leaf), was fractionated and concentrated. Active fractions were extracted from buds and freeze-dehydrated bud powder with petroleum ether, chloroform, acetone, and chloroform-methanol. These fractions possessed widely different properties from those of the polar fractions studied previously. Silicic acid column chromatography produced a series of related compounds having the properties of the polar lipids. Thin-layer chromatography and countercurrent distribution studies produced compounds that were probably pheophytins. When pheophytins a and b were isolated from the bud, they gave high feeding activity after significant purification. Pheophytin a from spinach also gave modest activity, but cotton pheophytin a was inactive after hydrolysis and reesterification with phytol. These and previous studies of the polar feeding-stimulant complex suggest that a multicomponent system is responsible for optimum feeding activity of the boll weevil.

Effect of Trifluralin on Roots of Corn and Cotton

Seed of corn (Zea mays L., var. Texas 28) and cotton (Gossypium hirsutum L., var. Deltapine smooth leaf) were planted in sand and subsequently drenched with solutions of α,α,α trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin). The levels of herbicide used inhibited growth of roots and shoots in both crops, but cotton proved more tolerant than corn. The roots failed to elongate normally, but the lateral growth that continued gave the radicle a “club-shaped” appearance, especially in corn. Stained sections of the roots were mounted as permanent slides for study. The cells at the extreme tip of the treated roots were small and dense; many were multinucleate. Immediately behind this region, the cells were abnormally large, thin-walled, and aberrant. A disorganized type of nuclear division was evident. Cell plate and cell wall formation were apparently rare. Although we found no normal sequence of mitosis in cells of treated roots, all stages of mitosis were seen in the untreated roots.

Constituents of the Cotton Bud. IX. Further Studies on a Polar Boll Weevil Feeding Stimulant Complex124

Techniques were used to concentrate and fractionate the polar feeding stimulant for the boll weevil, Anthonomus grandis Boheman, that is found in the buds of cotton, Gossypiun hirsutum L., Delta Pine Smooth Leaf. An active fraction could be extracted from freeze-dehydrated bud powder with water after successive extractions with several less polar solvents and, consequently, after removal of hydrocarbons, carotenoids, terpenoids, and flavonoids. The major active polar principle extractable with water was not absorbed on a weak cation exchange resin and was precipitated with lead ions. Studies by gel permeation suggested a moderate molecular weight <2000) for the active constituent (s) and eliminated proteins, large peptides, and polysaccharides with high molecular weights. Moderate feeding activity was found in methanol extracts of cotton buds in a fraction containing acidic components, but no active phenolic or carboxylic acid was isolated. Strong feeding activity was retained after fractions from methanol extracts were treated to remove or degrade flavonoid glycosides (and other glycosides), although 2 flavonoids with modest activity were isolated.

Effects of Irrigation Intensity and Nitrogen Level on the Performance of Eight Varieties of Upland Cotton, Gossypium hirsutum L.1

AbstractThe effects of four irrigation treatments and two levels of nitrogen on the performance of eight varieties of upland cotton were studied over a 3‐year period on Glendale silty clay loam at Yuma, Arizona.The varieties (‘Acala 44‐10,’ ‘Deltapine Smooth Leaf,’ ‘DeKalb 220,’ ‘Stoneville 7‐A,’ California Strains A and A‐65, and Arizona Experimentals 221 and 6010) tended to respond similarly to the irrigation treatments. Highest yields were obtained from all varieties under irrigations spaced 14 to 21 days apart with totals of 102 to 119 cm of applied water per season. Much lower yields were obtained from the “dry” irrigation treatments which approached depletion of the available soil moisture before each irrigation, with totals of 84, 84, and 64 cm of applied water, respectively, for the 3 years. Irrigation every 7 days, in 1963 and 1964, with totals of 147 and 160 cm of applied water produced yields of seed cotton almost as low as those from the dry treatments.Under the 14‐ and 21‐day irrigation schedules, application of ammonium sulfate at the rate of 224 kg N/ha, when compared with no applied nitrogen and with 84 kg N/ha, increased yields of seed cotton in all varieties. In 1963, application of 112 kg N/ha in midseason was equal to 224 kg N/ha applied before the first postemergence irrigation. Nitrogen level had no effect on yield under the dry 28‐day irrigation schedule. Under the wet 7‐day irrigation schedule, yields of Acala 44‐10 and Arizona Experimental 221 were reduced by high nitrogen while yields from the other varieties were unaffected or slightly increased.There was no consistent treatment effect on lint percentage or fiber properties.

A Laboratory Technique to Evaluate Boll Weevil Oviposition Preference Among Cotton Lines1

A technique was developed to evaluate a large number of cotton lines in a minimum of time as oviposition sites for the boll weevil. Mississippi field weevils and the A &amp; M laboratory strain were tested for a comparison of their response to various cotton lines. We concluded that: (1) Evaluating cotton lines with the laboratory strain of weevile would closely approximate the cotton varietal differences evident in evaluating with field weevils; (2) Boll weevil oviposition was an insect biological response which could be modified by the host plant genotype; and (3) ‘Triple Halhnark Sea Island,’ ‘Seaberry Sea Island,’ their F1 hybrid, ‘Brown Egyptian’, and Seaberry Sea Island ✕ Brown Egyptian were less preferred for oviposition by the boll weevil than ‘Deltapine Smooth Leaf.’

Differential Tolerance of Cotton Varieties to an Acid Soil High in Exchangeable Aluminum1

AbstractFourteen varieties of cotton, adapted to various regions of the Cotton Belt of the United States, were screened for AI tolerance by growing them for 56 days in a greenhouse on Al‐toxic Bladen clay loam (pH 4.4) treated with increasing levels of CaCO3. The varieties differed significantly in top growth on the unlimed soil and in their response to CaCO3 additions. In general, liming the acid soil to about pH 5.4 tended to equalize top yields of sensitive and tolerant varieties and permitted each to attain near maximum yield.Contrary to predictions, the varieties showing greatest tolerance to the acid soil, ‘Pima S‐2,’ ‘Acala 47–42,’ and ‘Acala 44–10,’ are western in origin and adaptation. Varieties showing the least tolerance were ‘Coker 100A,’ ‘Deltapine Smooth Leaf,’ and ‘Acala 1517D,’ which were developed in the Eastern, Delta, and Western regions, respectively. Differential tolerance between two extreme varieties, Coker 100A and Pima S‐2, was also reflected by root yields.These results suggest the possibility of breeding cotton varieties with even greater abilities to send their roots into acid subsoils of the Southeast, where shallow rooting of crops may be due, in part, to AI toxicity.

Constituents of the cotton bud—VII. : Identification of the anthocyanin as chrysanthemin

The only anthocyanin m cotton buds and flowers of Gossypium hirsutum L., var. Delta Pine Smooth Leaf, was identified as chrysanthemin, the 3-β-monoglucoside of cynidin. Buds and flowers contained 0-030 and 0-041 per cent pigment, respectively.

The Comparative Preference of Insects for Glanded and Glandless Cottons1

In field studies damage caused by Heliothis zea (Boddie) was the same for Rex Smooth leaf glanded and glandless cotton lines and glanded Deltapine Smooth Leaf. However, its damage was greater on glandless Acala than on glanded Acala cottons. Adult Maecolaspis flavida (Say) and Gastrophysa cyanea (Melsheimer), which normally do not damage glanded cotton, showed a marked feeding preference for all glandless lines. Alabama argillacea (Hubner) moths preferred to oviposit on glandless lines. Resulting larval feeding caused considerably more damage to all glandless than to glanded lines. Whether the insect preferences were a result of the glandless trait alone, or of other traits controlled by a gene or genes closely linked to the glandless genes was not determined. The data, particularly that relating to chrysomelids, indicated some of the potential insect problems associated with a desirable agronomical change in the biochemistry of the cotton plant.

Spanogonicus albofasciatus and Rhinacloa forticornis on Cotton in Arizona1

Sweep-net collections of Spanogonicus albofasciatus (Reuter) and Rhinacloa forticornis Reuter on cotton in 3 different years showed that S. albofasciatus was dominant in all years with its seasonal peak larger than and preceding that of R. forticornis . R. forticornis appeared to be a predator. Both species were abundant on weeds in cottonfields without being abundant on cotton itself. In cage tests the cotton plants easily tolerated feeding damage by S. albofasciatus and recovered quickly. Square shedding in the presence of this insect should probably be attributed to lygus bugs or to physiological causes. Test results indicated that natural populations would rarely damage cotton except in the seedling stage. A low reproductive rate of S. albofasciatus on Acala 4–42, Acala 44, and Deltapine Smoothleaf 3798 cotton varieties is suggested.