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- Author or Editor: A. L. Kenworthy x
Abstract
Objectives were to develop a non-electrical field fertilizer injection system for trickle irrigation and to determine fertilizer turnover rates for the system. Materials included a plastic tank(s), a flow regulating valve, and small I.D. inlet, outlet connector lines. Flow from the tank(s) was created by a pressure differential across the flow regulating valve. With post valve line pressure known, micro tubes for inlet, outlet lines were cut to lengths necessary for specific flow rates. Fertilizer turnover rates were determined by placing known quantities of KC1 in the tank(s) and collecting aliquots released from the tank(s) at half-cycle intervals (1 cycle = volume of tank). K concentration was determined by flame photometer. For a one tank system, 66% of fertilizer solution was removed per cycle. As tanks were added in series the depletion rate was reduced. This system is amenable to field trickle irrigation plots.
Abstract
Field experiments were conducted in 1967 and 1968 to determine the influence of succinamic acid 2,2-dimethyl hydrazide (SADH) on fruit ripening of the ‘Windsor’ sweet cherry. Foliar sprays of 1000, 2000, or 4000 ppm of SADH were applied to mature ‘Windsor’ trees. SADH promoted anthocyanin development by two weeks and sugar development by one week without significantly reducing fruit firmness. Treated fruits, however, were smaller than non-treated fruits of comparable color and sugar content. Fruit respiratory activity was not affected by SADH treatment.
It is postulated that SADH acts directly on the enzyme systems concerned with anthocyanin and sugar biosynthesis rather than acting at the hormonal level to advance the general physiological maturity of the fruit.
Abstract
In 4 experiments conducted to study internal bark necrosis (IBN) in apple, ‘Delicious’ trees were treated with Mn, Fe, Cu, and Al (100 and 200 ppm in nutrient solution), Mn, Fe, Cu, plus Al (50 ppm each) and a minus B treatment. Only trees receiving Mn and minus B developed IBN symptoms. Trees grown under normal and low levels of Ca and receiving variable concentrations of Mn (0, 25, 50, 75, and 100 ppm) developed IBN in proportion to Mn concentration. Spur-type and standard ‘Delicious’ trees did not differ in IBN severity. Bark samples with IBN symptoms, when analyzed on the electron microprobe x-ray analyzer, had greater Mn and Ca concentrations in necrotic tissue areas than in non-necrotic areas. IBN lesions induced with minus B had a higher Ca concentration in necrotic areas than in healthy tissue
Abstract
The effect of trickle irrigation on trunk diameter increase was studied with 4 shade tree species in 1973 and 1974. Irrigation treatments consisted of 5.7 liters per hour (2 gal/hr) and no supplemental water on sugar maple (Acer saccharum Marsh.) and honey locust (Gleditsia triacanthos L.). White ash (Fraxinus americana L. cv. Autumn Purple) treatments were no water, 1.4 liters per hour, and 2.8 liters per hour. Irrigated pin oak (Quercus palustris Muench.) trees received 5.7 liters per day at application rates of 5.7, 2.8, and 1.4 liters per hour and application time per day was 1, 2, and 4 hours respectively. Leaf analysis was performed each year.
In 1973 there was a doubling in increase in diameter of irrigated pin oak, white ash, and sugar maple with the higher flow rate per hour over that of checks. Irrigated honey locust trunk diameter increase was greater than checks. In 1974, 1 hr and 2 hr irrigated pin oak and irrigated white ash again outgrew checks but irrigated honey locust and sugar maple did not.
Leaf N and K were the only elements to show consistent changes with all species. Leaf N was lower in 1974 compared to 1973 while K was higher. Trickle irrigation did not promote any consistent significant change in nutrient composition of leaves.
Abstract
The relationship of trickle irrigation to root distribution was evaluated with sugar maple (Acer saccharum Marsh.), honey locust (Gleditsia triacanthos L.) and pin oak (Quercus palustris Muench.). Treatments were 5.7 liters per hour and no supplemental water. Trees were dug with a 66-inch tree space in 1974. The root system of each tree was cut into 15 cm concentric cylinders around the trunk. Roots were divided into those greater than 2 mm and those less than 2 mm in diameter. Fresh weight determinations were made with each root size classification in each zone.
Irrigation did not alter root system depth. Irrigated sugar maple had more fibrous roots (on a weight basis) and irrigated honey locust had more large roots than check trees. Irrigated pin oak had more fibrous roots and more large roots. Root systems of irrigated and non-irrigated trees were distributed in the same volume of soil.
Abstract
GA3 (0, 250, and 500 ppm) was applied at 75% full bloom to blueberry bushes caged with and without bees and to open pollinated bushes. GA3 significantly increased fruit yield per bush, reduced seed wt per fruit, and increased the rate of berry enlargement as compared to fruit not pollinated. No effect was observed on soluble solids and titratable acidity. GA3 appeared to substitute for the effect of pollination and fertilization.
Abstract
Foliar sprays of KNO3 were applied to young, N-deficient peach trees in 2 experiments over a 2-year period. Urea was compared with KNO3 in 1 year. Neither autumn nor spring applications of KNO3 or urea increased leaf N concn or tree growth significantly, although, in 1 year, the sprays delayed the onset of leaf senescence. By comparison, an autumn soil application of NH4NO3 significantly increased leaf N concn, terminal shoot growth, and trunk circumference.
Abstract
Vegetative and fruit responses of ‘Montmorency’ sour cherries to Alar were evaluated from 1966 to 1968. Mature trees were treated with from 1000 to 8000 ppm of Alar at 2 weeks after full bloom. Alar significantly increased fruit color and decreased the force required to separate the fruit from its pedicel early in the harvest season. These differences were sufficient to advance the start of commercial harvesting one week. Fruit firmness was significantly increased in both handpicked and mechanically harvested fruit. Alar treated fruit showed a significant ability to resist softening when mechanically harvested. Fruit color and firmness enhancement was evident in both canned and frozen processed fruit.
Alar altered the fruit growth curve and contributed to a more uniform size. Fruit acidity and respiration were significantly reduced. Alar reduced terminal growth, by reducing internode length, but increased flower bud initiation.
Abstract
Nitrogen was applied as a ground application at the recommended rate based on leaf analysis, or at 25, 50 or 100% of that rate injected through a trickle irrigation system in combination with 3 rates of water. Leaf N was not influenced by treatment. Fruit yield resulting from the ground application or the 100% and 50% injection treatments were equal, whereas the 25% injection rate gave variable results. Injection treatments had no marked effect on fruit size or fruit quality. N distribution within the tree was uniform where the trickle irrigation rate was 7.6 liters per hour. N levels in the leaves were lower at 15.2 liters per hour.