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Two vacuum machines, a single row 950 cfm and a 3 row 3000 cfm of air movement were tested. Treatments: 1) weekly vacuum, 2) Biphenthrin and 3) Untreated.
Biphenthrin treatments significantly reduced the number per plant of lygus nymphs (0.2) and adults (0.7) vs. the vacuum treatments (3.1) and (0.31) and Untreated (4.6) and (1.2) in both tests. Damaged fruit was significantly less in the Biphenthrin treatments (4.4%) from the vacuum (15.5%) and Untreated (21.5%) plots.
There was significant reduction in lygus numbers and fruit damage in the vacuum plot, but fruit damage remained unacceptably high. Minute pirate bugs were the least affected by the vacuum treatments. Lace wings and spiders were somewhat more affected and big eyed bug populations were reduced by over 50%.
Abstract
Controlled trickle irrigation applications in commercial strawberry [Fragaria xananassa Duch. ‘Heidi’] plantings in coastal California were used to estimate crop coefficients (Kc) relating applied water requirements to reference evapotranspiration (ETo) and Class A pan evaporation (Epan). The value of Kc increased with foliar growth during spring and leveled off at a relatively constant maximum through summer and early autumn. Since rates of ETo averaged 13% higher than Epan, lower Kc values were recommended for irrigation schedules based on ETo than for schedules based on Epan. The value of maximum Kc for ETo scheduling was fixed between 0.45 ≤ Kc ≤ 0.7, whereas the limits for Epan scheduling were 0.55 ≤ Kc ≤ 0.8. Upper Kc limits were established by scheduling small volume irrigations only as necessary to maintain favorable soil moisture conditions. Harvest results and soil matric potential measurements indicated that irrigations scheduled at the lower Kc limits could lead to production loss. An evaluation of grower irrigation practices showed that current applied water rates could be reduced significantly by scheduling irrigations with recommended Kc values.
Abstract
In field experiments using brussels sprouts (Brassica oleracea L., Gemmifera Group), cabbage (Brassica oleracea L., Capitata Group), cauliflower (Brassica oleracea L., Botrytis Group), and celery (Apium graveolens var. dulce L.), the application of nitrapyrin with ammonium sulfate fertilizer at planting produced higher yields than ammonium sulfate alone, at planting, or in split applications. Tissue levels of NO3-N of cabbage, cauliflower, and celery were usually significantly higher in nitrapyrin-treated plots than in those receiving comparable rates of Ν without nitrapyrin. Tissue levels of NO3-N in brussels sprouts did not increase significantly as Ν rate and yields increased.
Abstract
In the paper by O. E. Smith, N. C. Welch, and T. M. Little in J. Amer. Soc. Hort Sci. 98(6):529-533, November 1973, the following changes should be made on page 529, column 2, lines 28 and 35:
Line 28: change “transferred to a 1/15 M” to read “transferred to a 20-fold dilution of a 1/15 M”
Line 35: change “of the pH 7.0 phosphate” to read “of the pH 7.0 dilute phosphate”
If the buffer is used at 1/15 molar, the roots of the young plants will be injured due to the high osmotic strength of the buffer.
Abstract
Seed weight in lettuce was more important than seed width or thickness in predicting vigor. An air column separator was an effective way to separate seeds varying in weight. A biological assay called the slant test was developed to test vigor. The average root length after 3 days was used as a measure of vigor.
Abstract
Several lots of lettuce seed were separated into fractions varying in seed width and weight per seed. Seed vigor, as measured by the slant test, was found to vary in relation to seed weight. In field trials low vigor seeds emerged slower with less total emergence and produced smaller seedlings at thinning time than high vigor seeds. Head size at harvest and percent marketable heads were greater from high vigor seeds. It is suggested that seed vigor can be used to evaluate potential field performance of lettuce.
Abstract
Gibberellic acid (GA3) was applied to globe artichoke plants prior to bud enlargement in the fall, and to similar plants during bud development in the spring. Single applications of 25 or 50 ppm were adequate to induce accelerated flower bud development. The rate of bud development was more pronounced when GA3 was applied in the fall. Although total yields from treated and non-treated plants were not significantly different, earliness was increased.