Shedding Of Buds Research Articles

Importance of damage caused by bugs and caterpillars on flowers and other cotton fructiferous organs in a three-level program of phytosanitary protection in Togo

Bugs (Heteroptera), secondary devastators in comparison to caterpillars before 1980, constitute nowadays an important entomologic factor in the shedding of buds and new bolls. An evaluation of their damage and that of the caterpillars on shed organs was realized in an apparatus corresponding to a three method of protection. Statistical analyses (ANOVA) of results have shown in the first mode (NT) that the average of bugs’ damage on buds (49.25 ± 3.94) and new bolls (101.5 ± 6.65) is significantly higher than that of caterpillars (36.75 ± 3.25) and (51.75 ± 7.43) respectively. Treatments realized in the second mode (ST) allowed the reduction of the average of bugs’ damage by 31.50 ± 5.12 on buds and by 61.25 ± 2.75 on new bolls and that of caterpillars by 24.25 ± 2.62 and by 29.00 ± 4.43 respectively on buds and on bolls. The treatment of the third mode (PP) also led to a reduction of bugs’ damage by 24.25 ± 2.65 on buds and by 56.25 ± 7.20 on new bolls and respectively 16.25 ± 1.93 and 29.75 ± 3.06 the damage of caterpillars.

Linking physiological and architectural models of cotton

Despite the strong influence of plant architecture on crop yield, most crop models either ignore it or deal with it in a very rudimentary way. This paper demonstrates the feasibility of linking a model that simulates the morphogenesis and resultant architecture of individual cotton plants with a crop model that simulates the effects of environmental factors on critical physiological processes and resulting yield in cotton. First the varietal parameters of the models were made concordant. Then routines were developed to allocate the flower buds produced each day by the crop model amongst the potential positions generated by the architectural model. This allocation is done according to a set of heuristic rules. The final weight of individual bolls and the shedding of buds and fruit caused by water, N, and C stresses are processed in a similar manner. Observations of the positions of harvestable fruits, both within and between plants, made under a variety of agronomic conditions that had resulted in a broad range of plant architectures were compared to those predicted by the model with the same environmental inputs. As illustrated by comparisons of plant maps, the linked models performed reasonably well, though performance of the fruiting point allocation and shedding algorithms could probably be improved by further analysis of the spatial relationships of retained fruit.

Crown architecture in Quercus petraea and Q. robur: the fate of buds and shoots in relation to age, position and environmental perturbation

Shoot and bud dynamics of peripheral crown portions of mature pedunculate and sessile oak trees ( Quercus robur L., Q. petraea (Matt.) Liebl.) were monitored over almost three vegetation periods. The formation and shedding of buds and extension units (eus) was mapped in the form of simplified drawings. Branches were additionally subjected to manipulative treatments simulating herbivore (defoliation at different times, loss of certain bud types) and abiotic damage (artificial acid rain) and the effects on branch architecture analysed. Branch characteristics, such as branching order and age structure, had a large influence on the growth and dynamics of peripheral branch portions, even greater than that of the manipulative treatments, with the exception of spring defoliation and shoot tip removal, which led to increased shoot shedding. In order to quantify the observed changes in crown structure with time, new measures were introduced: the shedding ratio corresponds to the number of shed eus divided by the total number of eus present and produced since a given starting point. The vitality ratio was defined as the total number of eus produced in 1 year, divided by the total number of eus shed during the same time. The vitality ratio could thus be – on a small scale – the quantitative measure of Roloff's vitality classes (Roloff, 1987, 1988, 1989).

Early Season Development of Floral Buds in Cotton

AbstractImproving irrigation and pest control strategies in upland cotton (Gossypium hirsutum L.) requires a better understanding of the factors influencing the formation and retention of fruiting bodies. The objective of this study was to investigate the effect of irrigation regime, boll load, and fruiting position upon floral bud dynamics. Field experiments were conducted during 3 yr on a Gan Shmuel vertisol (clayey, montmorillonitic, calcareous, thermic Typic Chromoxerert). Treatments comprised four irrigation patterns, and one zero‐load (continuous flower removal) treatment. Dates of shedding, attainment of 1 cm size, and flowering were recorded by fruiting position for all buds on sympodia formed during the first 75 to 100 d after emergence. Of a total of 7972 buds observed, 51, 33 and 16% flowered, shed <1 cm size, and shed>l cm size, respectively. Shedding of buds <1 cm size was more sensitive to treatment than shedding of buds >1 cm size. The probability of bud formation at L2 and L3 was strongly affected by sympodium number (Ln represents the nth fruiting position on a sympodium). Flowering declined from 74% at L1 to 16% at L4. The zero‐load treatment achieved the highest flowering percentage (66%) and number of fruiting positions per sympodium. The lowest flowering percentage (42%) resulted from severe, and relatively late, water stress. Strong positive associations between the shedding of contemporary buds at different relative positions on the plant indicate that an important component of shedding is the response to common stress stimuli. Weaker negative associations between the fate of noncontemporary buds can be explained by the negative feedback of boll load on bud retention.

Flowering Pattern and Reproductive Efficiency of Oilseed Sesame

SUMMARYIn maximizing productivity levels in oilseed sesame (Sesamum indicum) one of the major constraints is the large-scale shedding of buds, flowers and capsules. The present study examines the reproductive behaviour of five sesame genotypes with a view to ascertaining the extent of production, shedding and retention of different reproductive organs. Sesame genotypes produce 250–350 flower buds per plant but shed most of them at different stages of development. Shedding is thus excessive, and 86–91% of the reproductive potential was not realized in this study, thus limiting yield. Improvement in yield through increased fruit retention is essential.