Abstract
β-1, 3-glucanase (laminarinase, EC 3.2.1.6) activity was detected in apples, asparagus, beets, cantaloupes, carrots, cherries, cucumbers, peaches, squash and tomatoes. During ripening in peaches and tomatoes, enzyme activities increased as fruit firmness decreased. Gel chromatography revealed that some of the extracts contained two β-1, 3-glucanases differing in molecular weight, pH optimum, and thermostability.
Bare soil, 13 different polyethylene mulching films, and K-Mulch kenaf paper film were compared to one another for use in early spring production of cantaloupe melons. The mulching treatments were applied to the top of raised beds spaced 200 cm apart in late January and seed of the cantaloupe variety Cruiser were planted in early February. Treatments were replicated five times in a complete randomized block design. Plots were irrigated throughout the season utilizing a drip irrigation system. Crop responses to mulches throughout the growing season were determined by measuring vine growth, fruit yield, Fruit quality and earliness. Mulch tensile strength was determined throughout the season, and ease of cleanup and disposal were evaluated after the growing season. Differences were recorded for treatments particularly regarding ease of cleanup.
In the fall of 1990, a new form of whitefly, tentatively identified as the poinsettia strain of Bemisia tabaci (Gennadius), was introduced into the agricultural regions of the desert southwest. Large densities of whitefly nymphs developed on cruciferous crops and substantial increases in pesticides for whitefly control were used. After overwintering in active stages on these crops, whiteflies moved into spring cantaloupes and developed moderate populations levels in some fields. In March, whiteflies migrated to newly-planted cotton and developed huge densities by August. At this time emerging fall cantaloupe was attacked and over 95% of this crop was destroyed by whitefly feeding. Whiteflies also developed to damaging numbers on alfalfa, grapes, citrus, crops not known to host the cotton strain of B. tabaci. Population densities remained high through the fall crucifer and lettuce seasons causing crop losses and delayed maturity. Damage estimates presently rest at roughly $122 million.
Field and laboratory experiments were conducted to study the effect of soil applied (Carbofuran) Furadan on watermelon and cantaloupe yields. Yields were significantly (p≤ 0.05) greater when Furadan was used than when it was not. The observed yield increases may have been due to factors other than just the insecticidal properties. Other systemic insecticides demonstrated no similar increase in yield. Yield increases were also evident even when plants were grown in sterile soil. Yield increase was due to a significant increase in the first harvest of watermelon and the first three harvests of cantaloupe. Numbers of fruit and average wt/fruit were increased for watermelon at the first harvest. Midwest growers usually receive the highest price per pound of watermelon at the first harvest. This significant increase in early harvest more than pays for the application of the chemical.
Cantaloupe (Cucumis melo L., cv. Hiline) were planted following over-wintering cover crops. In replicated field trials, stand development for 7 different cover crops and their effects on incidence of weeds, insects, diseases, and nematodes was assessed. Effects of cover crops on yield and quality of cantaloupe were evaluated. Cover crops evaluated were rye, crimson clover, lentils, subterranean clover, `Vantage' vetch, mustard, a polyculture of all cover crops and control-fallow. No insecticides were applied and only two applications of fungicides were made. Fertilizer applications were significantly reduced. No differences among cover crops for any of pest nematodes were observed. Significant differences in populations of beneficial and pest insects were observed. Polyculture had the highest plant vigor rating. The highest marketable yield occurred following crimson clover.
Abstract
‘Mainstream’ is a high yielding, small-fruited muskmelon (cantaloupe), Cucumis melo L. weigh 1.1-1.4 kg, have good keeping quality, a pleasing sweet taste, and are high in Vitamin C. The plants are compact and resistant to powdery mildew (Sphaerotheca fuliginea (Schlecht. ex Fr.) Poll.), downy mildew (Pseudoperonospora cubensis (Berk. & Curt.) Rostow., and cucumber beetles (Diabrotica undecimpunctata howardi Barber, Acalymma vittata (Fabricius), and Diabrotica balteata LeConte.
An instrument based on near infrared (NIR) reflectance techniques is described which is capable of determining nondestructively the percent soluble solids in whole honeydew, cantaloupe and watermelon samples. It utilizes a tilting interference filter technology for wavelength scanning and a silicon detector/amplifier for the detection of radiation which has penetrated through inner melon flesh. The standard error of prediction is of the order of 1.2 percent soluble solids for honeydew melons when compared with a standard refractometer analysis.
Abstract
The relationship of soluble solids content (SSC) to sensory quality of several cultivars of muskmelon (Cucumis melo L.) grown in Maryland or California was studied during 3 growing seasons (1970-1972). SSC above 8% was not always associated with high sweetness, flavor, or acceptability. SSC and external color were not highly correlated. Until the relation between SSC and sensory quality has been more thoroughly studied for today’s cultivars, sensory tests should be an integral part of all research involving quality of cantaloupes.
Monosporascus root rot/vine decline (MRR/VD), caused by Monosporascus cannonballus, is a serious disease of the major melon production areas of Texas, California, and Arizona. We have previously identified differing levels of tolerance in melon germplasm based on vine disease symptoms. This study was conducted to evaluate the yield response of commercial and experimental cantaloupe and honeydew hybrids subjected to MRR/VD. Thirty-nine and six cantaloupe and honeydew hybrids, respectively, were transplanted into a field highly infested with M. cannonballus in March 1995 in a randomized, complete block with 4 replications. The field was highly infested with Monosporascus cannonballus. `Caravelle' (very susceptible) and `Deltex' (tolerant) were included as control entries. Fruit were harvested at maturity and sized. Any fruit that did not mature completely due to vine death were counted as culls (unmarketable). Marketable yield of the cantaloupe entries ranged from 26.74% to 67.35%. The most tolerant hybrids were `SR103654', `Don Carlos', `Explorer', and `Ovation'. Marketable yield of the honeydews ranged from 8.43% to 41.46%, with `Morning Ice' and `Creme de Menthe' showing the most tolerance. The best performing hybrids were evaluated again the Fall 1995 and Spring 1996 seasons. In general, genotypes which matured later, and had a more dispersed fruit set, were more tolerant to MRR/VD. This supports previous data showing that high physiological stress (heavy, concentrated fruit load) leads to more severe and rapid vine collapse.
Abstract
Foam was applied for frost protection to January planted cantaloupes (Cucumis melo L.) in the Lower Rio Grande Valley of Texas. Two planting configurations consisting of shallow trenches and conventional beds were compared to evaluate volume of foam required and durability. The trench planting technique increased the foam’s durability and reduced the volume approximately three-fourths. The cost of foam application to a low profile crop in the shallow trenches was approximately $74.00 per hectare. Leaf temperature in the foamed trenches was up to 12°C warmer than nonfoamed conventional beds.