Stages Of Vegetative Development Research Articles

Patterns of14C-sucrose translocation in egg plant (Solanum melongenaL.)

SummaryPatterns of distribution of 14C-sucrose were determined in egg plant (Solanum melongena L.) cv. Arka Shirish at the vegetative, flowering and fruit development stages. 5 μCi of 14C-sucrose was fed to the fifth leaf from the top at each growth stage and the plants were harvested, 48 h after feeding or at later stages, and the distribution of l4C-sucrose determined. Results indicated bidirectional transport of assimilates to both apical and basal portions of the stem. Within 48 h 14C moved to all the plant parts; roots, stem and leaves appeared to be strong sinks until the fruit began to develop. In plants fed at the fruit development stage, the fruit below the fed leaf were a major sink, although considerable activity was traced in other plant parts also. Only at later stages of crop growth did the fruit become a strong sink. Even at the fruit development stage, about 5-8% of the activity was still found in the roots and no retranslocation to fruit was observed.

Predation and Food as Factors Affecting Survival of Nezara viridula (L.) (Hemiptera: Pentatomidae) in a Soybean Ecosystem

Direct field observations and use of radioactive phosphorus (32P) as a tracer showed 18 insect and 6 spider species, representing 6 orders and 19 families, to be predators of Nezara viridula (L.) in a soybean ecosystem in Louisiana. Solenopsis invicta Buren was the dominant egg predator during the vegetative stages of soybean development, while cannibalism of eggs by adults and nymphs of N. viridula was also frequently observed during this stage. Grasshoppers were the more important egg feeders during the reproductive stages of plant development. Life tables developed for N. viridula in field cages showed that survival to adult was 0.5% during the vegetative and flowering stages and 4.5% during pod set, but it increased significantly to 38.2% when seeds were formed. Under field conditions during the latter period, survival to fourth-instar nymphs declined to 8.7%, from which it was concluded that, in this particular ecosystem, 33.6% mortality was caused by predation and 57.7% was due to other factors.

SOYBEAN GROWTH RESPONSES TO ENHANCED LEVELS OF ULTRAVIOLET‐B RADIATION UNDER GREENHOUSE CONDITIONS

Soybean (Glycine max [L.] Merr. cv. Essex) was grown in an unshaded greenhouse under three levels of biologically effective ultraviolet‐B (UV‐BBE) radiation (effective daily dose: 0, 11.5 and 13.6 kJ m–2) for 91 days. Plants were harvested at regular intervals beginning 10 days after germination until reproductive maturity. Mathematical growth analysis revealed that the effects of UV‐B radiation varied with plant growth stage. The transition period between vegetative and reproductive growth was the most sensitive to UV‐B radiation. Intermediate levels of UV‐B had deleterious effects on plant height, leaf area, and total plant dry weight at late vegetative and reproductive stages of development. Specific leaf weight increased during vegetative growth but was unaffected by UV‐B during reproductive growth stages. Relative growth, net assimilation, and stem elongation rates were decreased by UV‐B radiation during vegetative and early reproductive growth stages. Variation in plant responses may be due in part to changes in microclimate within the plant canopy or to differences in repair or protection mechanisms at differing developmental stages.

Increasing Importance and Control of Mayweed Chamomile in Forage Crops1

AbstractMayweed chamomile (Anthemis cotula L.) is a cool‐season annual weed that germinates during March and matures by mid‐May in the southeastern United States. The economic importance of this weed in the pasture ecosystem has not been determined. The objectives of this study were: (i) to determine the forage quality of mayweed chamomile foliage; (ii) to survey the potential allelopathic influence of mayweed chamomile tissue extract on the development of certain forage species; and (iii) to evaluate herbicides for the control of this weed. The in vitro dry matter digestibility of mayweed chamomile ranged from 630 to 790 g kg−1, with the highest values residing in foliage harvested during the vegetative stage of plant development. Results of laboratory bioassays and growth chamber experiments indicated that water extracts of mayweed chamomile leaf material are potentially allelopathic to alfalfa (Medicago sativa L.) and Italian ryegrass (Lolium multiflorum Lam.) seedlings. Leaf tissue mixed in potting soil significantly reduced alfalfa and Italian ryegrass plant development. The extract and tissue concentrations used in this research were estimated to be similar to concentrations expected to occur within the pasture ecosystem. Paraquat (1,1'‐dimethyl‐4,4'‐bipyridinium ion) at 0.6 kg a.i. ha−1 and glyphosate [N‐(phosphonomethyl) glycine] at 1.2 and 2.4 kg a.i. ha−1 controlled mayweed chamomile in sericea lespedeza [Lespedeza cuneata (Dumont) G. Don] and bermudagrass [Cynodon dactylon (L.) Pers.] forage systems.

Corn Root Growth and Distribution as Influenced by Tillage and Nitrogen Fertilization1

AbstractTillage alters both soil physical and chemical properties, which in turn alter the environment for root growth and may impact on plant growth, nutrient uptake, and yield. The objective was to compare corn (Zea mays L.) root morphology and distribution in plots under minimum tillage (MT) for 7 yr to conventional tillage (CT) at N fertilization treatments of 0 and 180 kg N/ha. The 3‐yr field study was conducted in the Maryland Piedmont area on a Delanco silt loam (Aquic Hapludult). Three soil cores per plot were taken at vegetative, silking, and dough stages of plant development. A 76‐ mm‐diam steel tube was used to sample to a depth of 0.6 m in the plant row, at midrow (0.38 m), and half way between (0.19 m). The roots collected to 0.6 m accounted for an average of 82% of the total root weight present after grain harvest. Tillage did not significantly affect plant growth or grain yield. Conventional tillage significantly increased root dry weight in only 1 yr. Minimum tillage and N fertilization both increased root weight in the 0‐ to 0.07‐m layer in 2 of the 3 yr. Root mass decreased 90% in the 0‐ to 0.07‐m depth when samples were compared from in the row to 0.19 m away. Nitrogen fertilization decreased milligrams per meter of root and root radius in 2 of the 3 yr, allowing root length to increase in response to N without altering the weight of roots. Root growth was observed under drought and N stress conditions when shoot growth and yield were limited. The period of most rapid root development occurred in the 8 weeks following planting.

Environmental Effects on Growth and Development of Irrigated Soybeans with Different Growth Habits

Three soybean cultivars with a similar genetic background but different growth habits, Williams (Dt, -indeterminate), Will (Dt2-semideterminate), and Elf (dt1-determinate), were grown to determine their responses to different management practices. Cultivars were grown at two NE Kansas locations (Ashland and Rossville), in two planting dates (May and June), two row widths (38 and 76 cm), and two populations (30 and 60 plants/m2) under irrigation during the 1978 and 1979 growing seasons. The three cultivars maintained the same rank in plant height (Williams the tallest, Elf the shortest, and Will intermediate) in all environments. Row width did not consistently affect plant height. Stem dry matter accumulation (DMA) of Williams was higher than those of Will or Elf. Will and Elf accumulated more above-ground dry matter early in the season than Williams, initiating seed filling (R4 to R7) about a week earlier than Williams. However, Will reached physiological maturity (R7) a week earlier than Elf or Williams. The reproductive period from R6 to R7 proved to be significantly longer in Elf than in Will or Williams. New determinate and semideterminate cultivars adapted to the northern production region in the USA recently have become available. While most of the acreage in this region is dominated by indeterminate cultivars, the types new to the northern United States have performed well under a variety of production and environmental conditions. Soybeans possessing different growth habits have been studied and compared in their dry matter accumulation, vegetative and reproductive stages of development, and plant height, when grown under different management practices.

Shoot Development in Citrus sinensis L. (Washington Navel Orange). II. Alteration of Developmental Fate of Flowering Shoots after GA3Treatment

Initial stages of inflorescence and vegetative shoot development are described for Citrus sinensis (Washington navel orange). Budbreak occurred in early December, floral initiation in early January, and anthesis in late March. To ascertain when a resting bud was determined as an inflorescence, we treated buds at four stages in development, ranging from resting buds to those producing floral organs, with gibberellin (GA3) in situ. Examination of the shoots at maturity established that GA3 caused complete reversion of the potentially flowering resting buds, partial reversion for buds in early stages of breaking and initiating floral organs, and no significant reversion once the sepals were present. The terminal flower may show reversion to the vegetative state even after a sepal has been initiated, but the lateral buds were determined at initiation to be either thorns or flowers.

EFFECT OF PLANT DENSITY ON DEVELOPMENT AND YIELD OF RAPESEED AND ITS SIGNIFICANCE TO RECOVERY FROM HAIL INJURY

The ability of rapeseed crops (Brassica campestris L. ’Torch’ and B. napus L. ’Tower’) to recover from, and compensate for, loss of plants at the early vegetative stage of development was investigated by hand thinning plant populations established at commercial seeding rates with commercial seeding equipment. Plant density was reduced from 100-200 plants m−2 to 40 plants m−2 with less than a 20% loss in seed yield. Seeds per pod and seed weight in some instances increased with reduced plant density. However, compensation was attributed predominantly to an increased number of pods on the remaining plants, which increased from 20-90 to as many as 600. Branching increased from as few as 3 to, in some instances, almost 40. With reduced plant population there was a tendency for increased and prolonged accumulation of dry matter by the plants following flowering.Key words: Brassica campestris L., Brassica napus L., rapeseed, development, seed yield, hail.

Effect of Corn, Sugarbeets, and Fallow on Zinc Availability to Subsequent Crops

AbstractField observations indicated that Zn deficiency of beans (Phaseolus vulgaris L.) was sometimes more severe than expected when grown on fallowed soil that was low to marginal in available Zn. The objectives of this study were to determine the effects of fallow, sugarbeets (Beta vulgaris L.), and corn (Zea mays L.) on Zn availability to subsequent crops grown on a Portneuf silt loam (Durixerollic Calciorthids, coarse silty, mixed, mesic). The sugarbeet and corn plant tops and sugarbeet roots were removed, and 11.2 kg Zn ha−1 was applied on one‐half of each plot before fall plowing 25‐cm deep. Beans, sweet corn, or potatoes (Solanum tuberosum L.) were planted the following spring. Whole plant samples of beans and sweet corn and potato stems, leaflets, and petioles were sampled for chemical analyses during the growing season. All bean plants were Zn deficient when grown after fallow or sugarbeets but not after corn or where Zn fertilized. Potatoes and sweet corn did not show any Zn deficiency symptoms or any growth responses to Zn fertilization. The average zinc concentration in beans (vegetative development stage, V3) following corn was 20.5 mg kg−1 compared with 12.5 mg kg−1 following fallow or sugarbeets without Zn fertilization. The average Zn uptake by beans (V3) following corn was 1.3 g ha−1 compared with 0.6 g ha−1 after fallow or sugarbeets without Zn fertilization. The Zn uptake after corn was even greater than where 11.2 kg Zn ha−1 was applied to fallow or sugarbeets (1.3 vs. 0.9 g Zn ha−1). Enhanced Zn availability following corn persisted throughout the growing season and into a second bean crop, although at a decreased level. Similar trends occurred with potatoes and sweet corn. Soil DTPA‐extractable Zn was not significantly different after fallow, sugarbeets, or corn. These results indicate that Zn deficiency in sensitive crops may be alleviated or prevented depending upon the preceding crop grown, and that factors not measured by DTPA can significantly influence Zn availability.

Effects of supplemental ultraviolet-B radiation on the growth and physiology of field-grown soybean

Soybeans [ Glycine max (L) Merr. cv Essex and Williams] were grown outdoors in field plots during 1983 and 1984 under ambient and 2 supplemental levels of biologically effective ultraviolet-B (UV-B) radiation (daily supplemental dose: 3.0 or 5.1 effective kJ/m 2). These correspond to a 16 and 25% ozone reduction during clear sky conditions on the summer solstice. In 1983, neither cultivar showed any significant differences in growth, CO 2 assimilation, transpiration, stomatal conductance nor leaf water potential under enhanced levels of UV-B irradiation. By contrast in 1984, during late vegetative and early reproductive stages of development, leaf area and CO 2 assimilation in Essex were significantly reduced while stomatal conductance was increased by UV-B irradiation. At a later reproductive stage (full pod), UV-B induced effects were no longer evident except for a decrease in stomatal conductance. Williams remained unaffected throughout the entire season. These intraspecific response differences between years may be related to the frequency of drought and overcast skies. In 1983, plants experienced drought for long periods up to the full bloom stage, whereas in 1984 drought was less frequent and occurred only after the full pod stage. The study illustrates that the effectiveness of enhanced levels of UV-B radiation is related to several factors, including microclimatic conditions prevailing during the growing season, cultivar, and the stage of plant development.

Hepatic microsporidiosis of juvenile grey mullet, Chelon labrosus (Risso), due to Microgemma hepaticus gen.nov. sp.nov.

Abstract. Microgemma hepaticus gen.nov. sp.nov. is described from the liver of juvenile grey mullet, Chelon labrosus (Risso). Development occurs within xenomas (diameter 500μm) which have microvillar surfaces, encircling bands of mitochondria and a reticulate hypertrophic nucleus. Vegetative developmental stages, meronts, are plasmodial and divided by plasmotomy. These stages are enclosed by host membranes. Sporogonic stages are free in the cytoplasm and divide by multiple exogenous budding. Uninucleate spores (2·4μm × 4·2μm) possess 7–9 coils of the polar filament and a lamellar polaroplast. Xenomas are associated with liver connective tissue, and cause necrosis of adjacent liver cells in certain circumstances. Host response to infection involves leucocyte infiltration and granuloma formation, with spores being destroyed by repeated macrophage phagocytosis and necrosis and resulting in gradual resolution of the lesion. Although juveniles apparently tolerate large parasite burdens there is some evidence of a contribution by the parasite to stress‐related mortality. The transmission of the disease and its potentially high pathogenicity to larval fishes is discussed.

THE EFFECT OF SHADE STRESS ON THE PERFORMANCE OF CORN FOR SILAGE VERSUS GRAIN

A field study was conducted near Guelph, Ontario, to investigate the effects of shade stress on the yield of corn grown for silage versus grain. The effects of shading on the quality of whole-plant corn silage were also examined. Shade was provided by two layers of fiberglass screen, which reduced the amount of light by approximately 65%. The shade treatments were applied during either the vegetative, reproductive or grain-filling stages of development. Shading at any stage reduced whole-plant dry matter (WPDM) yield at the silage corn harvest stage and the level of this reduction was relatively independent of the stage at which the shade was applied. Grain DM yield at the grain harvest stage was also reduced by light stress, with the greatest reduction resulting from light stress during the reproductive stage. However, for silage production, high stover yield compensated for the reduction in grain yield, resulting in little reduction in whole-plant yield. Shading during either the reproductive or filling stage reduced WPDM content due to reduced grain content and higher stover moisture content.Key words: Corn, silage quality, whole-plant corn silage

The response of sorghum and sunflower to short-term waterlogging

Sunflower and sorghum were waterlogged for nine days at the vegetative, budsvisible/initiation or anthesis stage of development under glasshouse conditions to document the changes which occurred in the soil environment. These changes were also monitored in the absence of plants. At all three stages, there was a rapid reduction in oxygen concentration followed by denitrification. The loss of nitrate was much greater in the presence of sunflower and sorghum. Other components of the redox system, manganese and iron, exhibited a slow increase in concentration as the duration of waterlogging was extended. However, increases were more marked at the later growth stages. Ethylene could be detected at all stages of water-logging although the highest levels were recorded during the first twenty-four hours at the vegetative stage under sunflower and sorghum. Toxins such as nitrite, volatile fatty acids and carbon dioxide appeared unimportant in this experiment. Similarly, observations on a range of cations suggested that nutrient availability was not a factor in causing waterlogging damage. The above changes in the soil environment are discussed in relation to observed effects on plant growth.

Differentiation of vegetation zones and species strategies in the subalpine region of Mt. Fuji

The floristic and structural differentiation of vegetation along the altitudinal gradient in four subalpine forests of different developmental stages on Mt. Fuji has been studied. Near the forest limit a micropattern of vegetation corresponding to the altitudinal zonation has been observed which elucidated the mechanisms of development of the vegetation zonation. As to early stages of vegetation development only two types can be distinguished: the volcanic desert above 1500 m and the pioneer forests below. As to later stages a differentiation of subzones includes from higher to lower altitudes: the Alnus maximowiczii, Betula ermanii, Abies veitchii and Tsuga diversifolia forests. Larix leptolepis and Sorbus americana ssp. japonica, appear as co-dominants in ecotonal communities between the principal subzones and are also important pioneers in early stages. Similarity analyses reveal that the upper subalpine Alnus-Betula forests can be regarded as early successional phases of the climax Abies-Tsuga forests of the lower subalpine zone. The regular arrangement of A. maximowiczii-B. ermanii-A. veitchii is studied along the gradient from the margin to the interior of the forest growing near the forest limit where locally favourable conditions prevail. Growth form, height growth, photosynthetic activity, seed supply, and seedling distribution of the three principal species have been compared, as well as biomass and production relations in contiguous forests of these species. The marginal Alnus type community is productive and disturbance-tolerant, and has a wide ecological and sociological amplitude along the gradient, while the central Abies community is accumulative and disturbance-intolerant, and has a narrower tolerance range, but is superior in competition under stable habitat conditions. A vegetation organization, ‘temporal multi-storeyed structure’, is suggested which means that a zonal pattern of vegetation within a climax region develops by successive replacement of successional species along an environmental gradient.

Cultivar, Nitrogen, and Soil Water Effects on Apex Development in Spring Wheat1

AbstractA better understanding of the growth and yield determining traits of spring wheat (Triticum aestivum L.) is important to development of improved cultivars, management practices, and growth simulation models. The objectives of this research were to evaluate cultivars, soil water content, and fertilizer N with respect to development of the main stem apex under field conditions. The experiment was conducted over 4 years on a Williams loam soil (fine‐loamy, mixed Typic Argiborolls). Cultivars of hard red spring wheat and durum wheat (T. turgidum L.) averaged 17.6 and 20.2 days, respectively, from emergence to apex double‐ridge formation. Cultivars of hard red spring wheat also differed significantly in accumulated growing degree days (GDD) to double‐ridge formation. Plant growth stage at apex double ridge as determined by the Haun scale, differed among hard red spring wheat cultivars. In general, cultivars that had a longer vegetative apex development stage had a higher Haun score at double‐ridge formation and also higher grain yields. Apex development of the hard red spring wheat cvs. Olaf, James, and Alex grown with two fertilizer N levels and three soil water levels was affected more by cultivar than by soil water content or fertilizer N level. The seven‐leaf cv., James, compared with eight‐leaf cvs., Olaf and Alex, generally had a shorter duration apex vegetative growth stage and spikelet development stage, required fewer GDD to reach double‐ridge and terminal spikelet stages, and developed double‐ridges and terminal spikelets at a lower Haun score. Stepwise regression analyses indicated that differences in grain yield and spikes/plant at harvest could be partly explained by duration of apex development to double ridges and the terminal spikelet expressed in days, accumulted GDD, and Haun score. Yield and spikes per plant were also associated with the number of spikelets/spike.

A Photoperiod and Temperature Sensitive Period for Leaf Number of Maize1

The heat unit concept, e.g. Growing Degree Days, is used extensively to account for temperature effects on maize (Zea mays L.) development in models which attmept to predict crop development and yield. Environmental effects on rate and duration of leaf initiation, which determine final leaf number, have received much less attention in such models, although leaf number and the period from planting to silking are highly correlated for maize. Photoperiod and temperature are two environmental variables known to affect leaf number. The objective of this study was to delineate the sensitive period during which leaf number of the short‐season maize hybrid, Guelph GX 122, is influenced by photoperiod and temperature. Periods during which leaf number was influenced by temperature and photoperiod were determined by transferring plants to different photoperiod/temperature regimes at various stages of vegetative development. Leaf number was determined at tassel emergence and, in two of three experiments, leaf stage at which tassel initiation occurred was estimated by dissection of plants at regular intervals. All experiments were conducted in the environmentally controlled growth cabinets of the University of Guelph. Results of these experiments indicate that initiated leaf number of Guelph GX 122 was influenced by temperature between the five‐ and the seven‐leaf stage and by photoperiod betweenthe four‐ and the seven‐leaf stage. The transition from vegetative to reproductive development (i.e., tassel initiation) occurred a leaf stage which was numerically equal to 50% of final leaf number. Photoperiod and temperature effects on leaf number were additive for Guelph GX 122 grown under the conditions of these experiments.

First Harvest Phenological Stage Effects on Production of Eight Irrigated Grasses1

AbstractPhenological development stage at the first harvest affects seasonal dry matter production of some grass species. This field experiment was done to determine the effect first harvest phenological stage has on seasonal dry matter production of eight grasses under irrigation on the Central High Plains. Grasses were ‘Latar’ orchardgrass (Dactylis glomerata L.), ‘Fawn’ tall fescue (Festuca arundinacea Schreb.), ‘Regar’ bromegrass ( Bromus biebersteinii Roem. and Schult.), ‘Manchar’ bromegrass (B. inermis Leyss.), ‘Garrson’ creeping foxtail (Alopecurusarundinaceus Poir.), meadow foxtail (A. pratensis L.), ‘Luna’ pubescent wheatgrass Agropyron trichophorum (Link) Richt.], and ‘Greenar’ intermediate wheatgrass p. [intermedium (Host) Beauv.]. Soil of the study area was an Altvan fine sandy clay loam, an Aridic Argiustoll. First harvests of the grasses were made at the vegetative, boot‐heading, and anthesis stages of development. In 24 species by year combinations, dry matter production was greater for first harvest at the boot‐heading stage than for vegetative and anthesis stages by eight and five harvests, respectively. First harvest at the anthesis stage had greater dry matter production than for boot‐heading in only one instance. First harvest at the vegetative stage depressed seasonal dry matter production. Crude protein and in vitro dry matter digestability (IVDMD) production generally followed the dry matter yields of the forages. Since the foxtail grasses have an indeterminate heading stage, a forage height of 25 to 30 cm appeared to be the best guide for first harvest of the growing season. The foxtail grasses, Latar orchardgrass, Fawn tall fescue, and Regar meadow bromegrass gave consistent season long production. The wheatgrasses and Manchar smooth bromegrass produced little regrowth and can be used to the best advantage in a forage program where hay harvest at the flowering stage is practiced.

Description of Sunflower Growth Stages1

A standardized, accurate, and easy system is needed to describe sunflower (Helianthus annuus L.) plant development. The objective of this study was to develop and describe stages of sunflower plant development in a manner which is simple but accurate.Plants were divided into either Vegetative (V) or Reproductive (R) stages of plant development. Vegetative development is divided into two phases, emergence and true leaf development. The latter stages are determined by the number of true leaves in excess of 4 cm in length. The number of vegetative stages is dependent upon the number of true leaves formed by the plant, making the method flexible but accurate. The reproductive development was divided into nine stages based on the development of the inflorescence from its initial appearance through anthesis to physiological maturity of the seed. This method of describing the stages of development in sunflower is rapid, accurate, greatly simplifies current methods, and can be used to determine plant development for either single or branched inflorescence sunflower.

Functional aspects of Abscisic Acid Metabolism in Cotyledons of Phaseolus vulgaris L. Seedlings

During the early stages of germination and vegetative development, cotyledons of intact bean (Phaseolus vulgaris L.) seedlings showed active ABA catabolism causing a low endogenous ABA content. At the end of the substrate mobilizing phase, when the cotyledons became senescent, a drastic increase of the endogenous ABA content linked with a decrease of the ABA catabolic activity was observed. This indicates that a close connection exists between senescence and endogenous ABA content and metabolism in bean cotyledons. Removal of the apical growth region induced in the cotyledons activation of the ABA catabolism and the endogenous ABA concentration decreased below the detection limit (0.1 ng/g fr wt) at the onset of the outgrowth of the axillary buds. From then, apical dominance was restored and the cotyledons returned to the senescent state, which was correlated with a drastic increase of their endogenous ABA content.

Influence of Induced Lodging on Pod Distribution and Seed Yield in Soybeans1

AbstractLodging occurs frequently in soybeans [Glycine max (L.) Merr.] and has been shown to reduce yields of indeterminate cultivars under most conditions: Information is limited on effects of lodging on determinate cultivars, types commonly grown in the southern U. S. Influence of lodging on pod distribution and seed yield was measured during a 2‐year study in the field on ‘Forrest’, a determinate cultivar and ‘R74‐334’, a semideterminate strain, at three stages of growth. Growth of the semideterminate strain in Arkansas resembled that of indeterminate cultivars grown in the Midwest. Plants were lodged at 0°, 45°, and 90° angles from the vertical at a vegetative stage (V8) and two reproductive stages (R2 and R4).A significant yield reduction was obtained from induced lodging at full pod (R4) but none at the vegetative (V8) or full bloom (R2) stage of development. The determinate cultivar and semideterminate strain were affected similarly by the lodging treatments. Lodging resulted in an increase in percentage of pods on lateral branches at stages V8 and R2 but no change was noted at R4. Number of seeds per pod was not affected by plant lodging. Lodging affected the number of seeds per plant more than seed size. Decrease in seed yield, therefore, was primarily due to reduction in number of seeds produced on lodged plants.