Early Fruit Yield Research Articles

Effect of Concentration of Nutrient Solution on Vegetative Growth and Fruit Yield of Hydroponically Grown Tomato Plants.

Tomato (Lycopersicon esculentum Mill. ev. Ogatazuiko) plants were grown in low concentration (a quarter of the control levels) or control (full strength Yamasaki's tomato solution until 7 weeks, and then 1.5 fold strength) . The EC of the low nutrient solution was adjusted daily to avoid deficiency of nutrient supply. There was significant reduction in leaf dry weight, stem dry weight, crop growth rate (CGR) and leaf area index (LAI) of plants grown in low nutrient solution after 6 weeks. These differences were present for the next 9 weeks. There were no significant differences in root dry weight, total number of fruits and early fruit yield, but the total fruit yield from plants grown in low nutrient solution was 32% less than that from the control plants. The relative amount of assimilate in the fruit and the net assimilation rate (NAR) of plants grown in low nutrient solution was significantly greater than the control plants from week 6 to week 12, however, it was less than the control plants at week 15. The concentration of nutrient solution had no effect on the P, Ca and Mg content in leaves, but the N and K content in leaves was significantly lower in plants grown in low nutrient solution than in control plants at week 15. The experiment showed that it is possible to control excessive vegetative growth without the loss of fruit yield by the use of a low concentration of nutrient solution (EC 0.7-0.9 dS/m) with the frequent supplementing of N and K after topping.

POTASSIUM SOURCE AND RATE AND CALCIUM RATE EFFECTS ON TOMATO YIELD AND QUALITY.

Tomatoes (Lycopersicon esculentum Mill.) were grown on a sand and loamy sand to evaluate the effects of K source, K rate, and Ca rate on plant nutrient uptake, fruit yield, and fruit quality. The K was applied at 200 and 400 kg K·ha-1 from KCl and K2SO4. Gypsum was applied at 0, 450 and 900 kg Ca·ha-1. On the sand, tomato N leaf tissue concentrations were higher with K2SO4 than KCl. Leaf K concentrations were higher and Ca contents were lower with the higher than lower K rate. At first fruit harvest, leaf Ca concentrations were linearly increased with an increase in Ca rate. Early and total fruit yields, however, were not influenced by K source, K rate, or Ca rate at both locations Marketable fruit were more firm with K2SO4 than KCl and with 200 than 400 kg K·ha-1 on the sand. Fruit were less firm on the sandy loam than sandy soil but was not affected by K source or rate on the former soil. Ca rate had no effect on fruit firmness on either soil. Fruit citric acid contents were higher with KCl than K2SO4 and with 400 than 200 kg K·ha-1, Fruit color and percentage dry weight were not affected by treatment.

Yield of Trickle-irrigated Tomatoes as Affected by Time of N and K Application

Tomatoes (Lycopersicon esculentum Mill.) were grown on polyethylene-mulched beds of an Arredondo fine sand during two seasons to evaluate the effects of trickle-applied N and/or K, percentages of trickle-applied N and K (50%, 75%, and 100%), and schedules of N and K application on fruit yield, and leaf and shoot N and K concentrations. The daily irrigation requirement, calculated at 47% of the water evaporated from a U.S. Weather Service Class A pan (Epan), was met by the application of 4.6 mm to 7.2 mm water/day. Fertilizer was injected weekly in a variable (2% to 12.5% of the total amount weekly) or constant (8.3% of the total amount weekly) schedule during the first 12 weeks of each season. Trickle-applied nutrients and trickle-applied percentage of nutrients interacted in their effects on early, midseason, and total marketable fruit yields. When N + K and N were trickle-applied, the mean early total marketable fruit yield decreased linearly from 25.3 t·ha-1 to 16.3 t·ha-1 as the trickle-applied percentage of nutrients increased from 50% to 100%; but when K was trickle-applied (100% preplant-applied N), yields were not affected by the trickle-applied percentage (mean 26.3 t·ha-1). The weekly schedule of N and K injection had no effect on fruit yield or other characteristics. Higher leaf N and K concentrations early in the season were obtained when the respective nutrient was 50% to 100% preplant-applied than when the respective nutrient was 75% to 100% trickle-applied; but late in the season, higher concentrations were obtained when the respective nutrient was trickle-applied. Higher yields, however, were associated with higher early season leaf N concentrations rather than with higher late-season leaf N or K concentrations.

A heat unit system for predicting optimum row tunnel removal time for bell peppers

A heat unit (heat sums) system to determine optimum row tunnel removal time to produce the maximum early and total fruit yield of bell peppers ( Capsicum annuum L.) was developed. The optimum heat unit over 3 years was 647–678, using a base temperature of 10°C. Ambient temperatures recorded outside (but nearby) the tunnels were a better predictor of high and low temperatures inside the tunnels than local weather service data. Equations were developed and presented which allow the use of ambient temperatures to estimate tunnel temperatures and predict total heat units under the tunnels.

The inheritance of fruit yield and stolon production in everbearing strawberries

The everbearing progeny from crosses between three short-day and four everbearing genotypes were assessed for early fruit yield and stolon production. General combining ability (GCA) was found to be important for fruit yield but specific combining ability (SCA) was more important for stolon production. The results suggested that it should be possible to combine early fruiting and adequate stolon production in an everbearing genotype. The breeding strategy necessary to achieve this aim is discussed.

Effect of Root Container Size and Location of Production on Growth and Yield of Tomato Transplants

Abstract ‘Pik-Red’ tomato (Lycopersicon esculentum Mill.) transplants produced in 2 locations (Florida and Michigan), in 6 root cell sizes were compared for fruit productivity in Michigan. Transplants grown in large cells produced more early yields than those from small cells, but generally did not produce more total yields. Large root cell size had a greater effect on transplant size than did wide spacing in the flat. Speedling root cell size 175 (39.5 cm3) produced the largest transplants, the largest early fruit yields, and the greatest weight of marketable fruit. Transplants grown in Speedling trays in Michigan produced larger early yields than Speedling transplants grown in Florida.

The effects of propagation temperature, CO2concentration and early post-harvest night temperature on the fruit yield of January-sown cucumbers

SummaryGrowth and fruiting responses of four January-sown cucumber cultivars to two propagation temperatures (day 21°C, night 19°C and day 24°C, night 17°C), three levels of CO2 enrichment (400, 1000 and 1600 vpm) and three stages of post-planting night temperature reduction (0, 3 and 6 weeks after first harvest) were examined in a glasshouse experiment. Early (4-week) fruit yield and monetary returns were significantly increased when the higher day temperature treatment was combined with the 1600 vpm CO2. The early advantage was soon lost and after 20 weeks harvesting there were no differences between the propagation temperature treatments. After two weeks of CO2 treatment total dry weight of aerial parts, leaf area and stem length were increased by 88, 73 and 69% respectively when the CO2 level was raised from 400 to 1000 vpm. A further rise from 1000 to 1600 vpm produced no further increases indicating that 1000 vpm is probably near the optimum concentration for growth at the temperatures applied. In the early (4-week) harvest period, fruit yield and gross monetary returns increased by c. 30% when CO2 was raised from 400 to 1000 vpm but there was little or no difference between plants grown in 1000 or 1600 vpm. The early yield advantage from enrichment at 1000 vpm CO2 was maintained throughout the season (20 weeks of harvesting). The most economic level of CO2 enrichment for January-sown cucumbers was c. 1000 vpm. Lowering night temperature at the start of harvesting reduced fruit yield and monetary value compared with lowering the temperature 3 or 6 weeks after fruit picking commenced. The estimated savings in fuel from this treatment were too small to offset the loss of revenue from the crop. The most economic time to reduce night temperature in the January-sown crop was 3 weeks after the start of harvesting.

Artificial Lighting and Spacing as Photosynthetic and Yield Factors in Winter Greenhouse Tomato Culture1

Abstract Photosynthetic and yield responses of tomato, Lycopersicon esculentum L., ev. Tuckcross V and Tuckcross 533 supplemental lighting and spacing were studied during the unusually dark winter of 1972–73. Supplemental lighting and wide spacing increased total flowers, % fruit set, fruit size, and total fruits/plant. and contributed to greater early and total fruit yields. The increases were related to increased apparent photosynthetic rate and efficiency. Supplementary top lighting (184 W/m2) increased fruit weight/plant 1107 g/plant (89%) over natural lighting for an increase of 6.0 g/plant for each watt/m2. Supplementary top + side lighting (368 W/m2) increased fruit weight 2853 g/plant (121%), an increase of 7.7 g/plant for each watt/m2. Maximum fruit yield/plant was obtained with top + side lighting at a spacing of 50.8 × 41 cm in a staggered double row bed. Plant spacing of 38.1 × 41 cm with maximum lighting gave greatest yield/unit area. Photosaturation was not attained bv supplementary lighting.

Effect of Benzothiazole-2-Oxyacetate on Flowering and Fruiting of Papaya

1. A preliminary experiment showed that 4-month-old Solo Line 8 papaya plants, sprayed with benzothiazole-2-oxyacetic acid (B-2-OA) in August before flowering, flowered in less time and at a lower node than plants sprayed with TIBA, NAA, or IAA. Sprays of B-2-OA resulted in higher early fruit yield. Differences in yield diminished during subsequent harvests. 2. When NaB-2-OA was applied to juvenile papaya trees in mid-October, the threshold concentration of the flowering response was found to be between 20 and 30 p.p.m. The number of nodes to the first flower decreased at the rate of about one node per 10 p.p.m. increase in concentration. The early yield, as indexed by number and weight of fruit, was materially increased. 3. The earlier flowering and increased yields of earlier harvests may be economically advantageous.