scholarly journals GROWTH RESPONSES OF WATERMELON ON WAVELENGTH SELECTIVE MULCHES AND VISPORE ROW COVER IN MISSOURI

HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1177c-1177
Author(s):  
Mack A. Wilson ◽  
Victor A. Kahn

The influence of VisPore row cover and four synthetic mulches on the growth and yield of watermelons were studied. Row cover and synthetic mulch treatments consisted of VisPore row cover, IRT-76 (green), AL-0R (brown), clear and black polyethylene mulches. VisPore was used with a combination of' four mulches and two controls (VisPore alone and bare soil). Significant differences were observed by orthogonal comparison when no row cover (NRC) was compared to row cover (RC) on the number '000/acre of marketable `Crimson Sweet' watermelons. Total, marketable and percent marketable yields were significantly different when orthogonal comparison were performed on NRC vs. RC. Yields were greater when RC vs. NRC treatments were used on `Crimson Sweet' watermelons.

2017 ◽  
pp. 44-54
Author(s):  
Zenaida Gonzaga ◽  
Warren Obeda ◽  
Ana Linda Gorme ◽  
Jessie Rom ◽  
Oscar Abrantes ◽  
...  

Okra or Lady’s finger, botanically known as Abelmoschus esculentus (L.) Moench, is a tropical and sub-tropical indigenous vegetable crop commonly grown for its fibrous, slimy, and nutritious fruits and consumed by all classes of population. It has also several medicinal and economic values. Despite its many uses and potential value, its importance is under estimated, under-utilized, and considered a minor crop and little attention was paid to its improvement. The study was conducted to evaluate the effects of different planting densities and mulching materials on the growth and yield of okra grown in slightly sloping area in the marginal uplands in Sta. Rita, Samar, Philippines. A split-plot experiment was set up with planting density as main plot and the different mulching materials as the sub-plot which were: unmulched or bare soil, rice straw, rice hull, hagonoy and plastic mulch. Planting density did not significantly affect the growth and yield of okra. Regardless ofthe mulching materials used, mulched plants were taller and yielded higher compared to unmulched plants. Moreover, the use of plastic mulch resulted to the highest total fruit yield. The results indicate the potential of mulching in increasing yield and thus profitability of okra production under marginal upland conditions.


Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 412
Author(s):  
Ivan Bjelanovic ◽  
Phil Comeau ◽  
Sharon Meredith ◽  
Brian Roth

A few studies in young mixedwood stands demonstrate that precommercial thinning of aspen at early ages can improve the growth of spruce and increase stand resilience to drought. However, information on tree and stand responses to thinning in older mixedwood stands is lacking. To address this need, a study was initiated in 2008 in Alberta, Canada in 14 boreal mixedwood stands (seven each at ages 17 and 22). This study investigated growth responses following thinning of aspen to five densities (0, 1000, 2500, 5000 stems ha−1 and unthinned (control)). Measurements were collected in the year of establishment, and three and eight years later. Mortality of aspen in the unthinned plots was greater than in the thinned plots which were not significantly different amongst each other. Eight years following treatment, aspen diameter was positively influenced by thinning, while there was no effect on aspen height. The density of aspen had no significant effect on the survival of planted spruce. Spruce height and diameter growth increased with both aspen thinning intensity and time since treatment. Differentiation among treatments in spruce diameter growth was evident three years from treatment, while differentiation in height was not significant until eight years following treatment. Yield projections using two growth models (Mixedwood Growth Model (MGM) and Growth and Yield Projection System (GYPSY)) were initialized using data from the year eight re-measurements. Results indicate that heavy precommercial aspen thinning (to ~1000 aspen crop trees ha−1) can result in an increase in conifer merchantable volume without reducing aspen volume at the time of harvest. However, light to moderate thinning (to ~2500 aspen stems ha−1 or higher), is unlikely to result in gains in either deciduous or conifer merchantable harvest volume over those of unthinned stands.


1980 ◽  
Vol 58 (20) ◽  
pp. 2200-2205 ◽  
Author(s):  
S. Asimi ◽  
V. Gianinazzi-Pearson ◽  
S. Gianinazzi

Growth and yield increases, obtained in nodulated soybeans growing in unamended sterile soil by inoculation with the vesicular–arbuscular (VA) mycorrhizal fungus Glomus mosseae, were accompanied by improved P uptake, lower root to shoot ratios, better nodulation with higher nitrogenase activity, and modifications in the pattern of the latter during plant growth. Stimulation of nitrogenase activity occurred early in plant development and preceded plant growth responses by about 2 weeks. Phosphate fertilization increased yield, percent P but not percent N of both mycorrhizal and nonmycorrhizal soybeans, and also modified the pattern and amount of nitrogenase activity during plant growth. Additions of 0.25 g KH2PO4/kg to the soil eliminated the mycorrhizal effect on plant growth, but nodule formation and nitrogenase activity were still significantly stimulated by the mycorrhizal infection. Mycorrhizal effects on nodulation were eliminated with 0.5 g KH2PO4 and on nitrogenase activity with the addition of 1.0 g KH2PO4. These higher levels of phosphate fertilization considerably diminished infection and, in particular, fungal spread within the roots.


2019 ◽  
Vol 49 (11) ◽  
pp. 1471-1482
Author(s):  
Woongsoon Jang ◽  
Bianca N.I. Eskelson ◽  
Louise de Montigny ◽  
Catherine A. Bealle Statland ◽  
Derek F. Sattler ◽  
...  

This study was conducted to quantify growth responses of three major commercial conifer species (lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco), and spruce (white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex. Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière))) to various fertilizer blends in interior British Columbia, Canada. Over 25 years, growth-response data were repeatedly collected across 46 installations. The fertilizer blends were classified into three groups: nitrogen only; nitrogen and sulfur combined; and nitrogen, sulfur, and boron combined. The growth responses for stand volume, basal area, and top height were calculated through absolute and relative growth rate ratios relative to a controlled group. Fertilizer blend, inverse years since fertilization, site index, stand density at fertilization, and their interactions with the fertilizer blend were used as explanatory variables. The magnitude and significance of volume and basal area growth responses to fertilization differed by species, fertilizer-blend groups, and stand-condition variables (i.e., site index and stand density). In contrast, the response in top height growth did not differ among fertilization blends, with the exception of the nitrogen and sulfur fertilizer subgroup for lodgepole pine. The models developed in this study will be incorporated into the current growth and yield fertilization module (i.e., Table Interpolation Program for Stand Yields (TIPSY)), thereby supporting guidance of fertilization applications in interior forests in British Columbia.


2018 ◽  
Vol 1 (1) ◽  
pp. 168-178 ◽  
Author(s):  
Ritesh Kumar Jha ◽  
Ram Babu Neupane ◽  
Abishkar Khatiwada ◽  
Shailesh Pandit ◽  
Bhishma Raj Dahal

Okra (Abelmoschus esculentus L.) is one of the most important vegetable crop of Nepal. Its yield and growth parameters are affected by different cultural practices. This study was conducted at Olericulture Farm of Agriculture and Forestry University, Rampur, Chitwan, Nepal during April 29 to July 9 of 2018. The field experiment was carried out in split plot design using three replications. The treatments consisted of three intra row spacing (30, 45 and 60 cm) and four different mulching materials (Silver plastic, Panicum repens, Lantana camara and bare soil). The objective of this experiment was to assess the effects of various intra-row spacings and mulching materials on growth and yield of okra. The effect of mulching materials on okra yield was found significant. The okra yield was highest (8104 kg/ha) under silver plastic mulch followed by control (5161kg/ha), Panicum repens (3901kg/ha) and Lantana camera (3701kg/ha), respectively. Silver plastic mulch enhanced the growth parameters like canopy length, plant height, leaf number, leaf length, girth and yield of okra. The spacings provided non significant effect on okra yield, however the yield of okra was highest (7295 kg/ha) under 30×30 cm spacing followed by 45×30 cm (4660 kg/ha) and 60 cm × 30 cm spacing (3703 kg/ha), respectively. Combination of silver plastic mulch along with 30 cm × 30 cm spacing provided the highest okra yield. This study suggests that farmers of the Chitwan should grow okra at spacing of 30 cm × 30 cm and under silver plastic mulch to produce higher yield.


1989 ◽  
Vol 19 (2) ◽  
pp. 247-256 ◽  
Author(s):  
V. C. Baldwin Jr. ◽  
D. P. Feduccia ◽  
J. D. Haywood

This study compared growth responses in planted loblolly pine (Pinustaeda L.) and slash pine (P. elliottii Engelm.) stands thinned by using three row-felling methods and at the same density levels, three selective felling methods. The study plots were in six plantations, aged 15–22 years, located in central Louisiana. Growth was measured 5 and 10 years after plot installation. Site index varied from 19.5 to 31.7 m (base age 50) and initial planting densities ranged from 1993 to 2989 trees/ha. Study results show there will likely be less diameter increment and less net basal area and cubic-metre volume per unit area growth and yield, and the growth will be in smaller-sized trees, if row thinning is used rather than selective thinning from below. These differences will probably be greater in slash pine plantations than in loblolly pine plantations.


2015 ◽  
Vol 7 (2) ◽  
pp. 1064-1069 ◽  
Author(s):  
Kanchan Pahwa ◽  
Navita Ghai

A phytohormone may be defined as an organic substance other than a nutrient active in very minute amounts which is formed in certain parts of all plants and which is usually translocated to other sites, where it evokes specific biochemical, physiological and morphological responses. The gaseous plant hormone ethylene modulates many internal processes and growth responses to environmental stimuli. Ethylene is known to exert its effects by altering gene expression both at transcriptional and post-transcriptional level. Ethylene has long beenrecognized as a growth inhibitor, but evidence is accumulating that ethylene can also promote growth. Therefore, the concept of ethylene as a general growth inhibitor needs reconsideration. Different authors screened various concentrations viz. 100 ppm, 150 ppm which promotes the plant growth in groundnut, soybean, mustard, barley, pigeonpea etc. The lower concentration of ethylene (100ppm) has increased the yield by 17 percent in pigeonpea. It increased the yield by manipulating source-sink relationships and flower retention The present study highlights the various processes of growth stimulated by ethylene and its use in enhancing yield of various crop species. It could be inferred that lower concentration of ethrel sprayed at pre-flowering stage promoted the growth and yield of various crops (barley, corn, groundnut, pigeonpea, soybean etc.).


Weed Science ◽  
2015 ◽  
Vol 63 (3) ◽  
pp. 710-722 ◽  
Author(s):  
Neith G. Little ◽  
Charles L. Mohler ◽  
Quirine M. Ketterings ◽  
Antonio DiTommaso

Sufficient fertility is important for crop growth and yield but supplying a balanced amount of N, P, and K with compost and manure is a challenge and nutrient imbalances can benefit weeds more than crops. The goal of this study was to compare the aboveground growth responses of common northeastern U.S. crops and weeds to addition of composted poultry manure (CPM). A secondary goal was to test whether the observed growth responses to CPM could be attributed to the three macronutrients—N, P, and K—supplied in the CPM. Two field experiments were conducted over 2 yr. Species grown were corn, lettuce, kale, Powell amaranth, common lambsquarters, giant foxtail, and velvetleaf. Plants were grown in soil amended with CPM or single-nutrient organic N, P, and K fertility amendments. Single-nutrient P treatments with bone char did not adequately mimic P supply from CPM. In both years, biomass of all weeds studied increased with CPM amendment rate. Powell amaranth was the most responsive to CPM addition, increasing 1,775 and 159% from the control to the highest CPM rate in 2010 and 2011, respectively. Corn biomass increased by 22% with CPM rate in 2010 but did not increase with CPM rate in 2011. Lettuce biomass increased with CPM amendment rate (175% in 2010 and 109% in 2011), but due to the increased weed biomass at high CPM amendment rates, good weed control will be necessary to maintain this yield benefit. The increase in growth of Powell amaranth, common lambsquarters, and giant foxtail with CPM amendment was not due to N or K, and may have been influenced by P or another factor in the CPM. Velvetleaf was the only species that exhibited increased biomass with N addition (as blood meal), similarly to the increase with added CPM, suggesting the velvetleaf growth response to CPM was due to N in the CPM. The results show that nutrient ratios should be considered when applying organic amendments, because application rates of organic amendments that meet the crop's needs for one nutrient may oversupply other nutrients. Overfertilization will not benefit crop yield, but the results of this study show that high organic fertility application rates are likely to increase weed growth.


2016 ◽  
Vol 46 (5) ◽  
pp. 645-655 ◽  
Author(s):  
Justin L. Pszwaro ◽  
Anthony W. D’Amato ◽  
Thomas E. Burk ◽  
Matthew B. Russell ◽  
Brian J. Palik ◽  
...  

Red maple (Acer rubrum L.), historically a common but not abundant tree species in North America, has increased in abundance throughout its range over the last several decades; however, it has received little attention in growth and yield studies. The objectives of this study were to (i) evaluate the effects of stocking level and stand density on overall patterns of red maple stand productivity and (ii) quantify these relationships across a wide range of stand age, site quality, geographic location, and climatic conditions. We used long-term measurements from 52 sites in Wisconsin and Michigan to examine growth responses of even-aged red maple stands to various levels of thinning. Using linear, mixed-effects modeling, future stand-level red maple basal area was modeled as a function of stand and plot characteristics and climatic variables. Growing season precipitation and its interaction with initial red maple basal area were significant predictors; however, they only collectively reduced the mean squared error by 2.1% relative to a base model containing solely stand and plot factors. Model projections indicated there was little difference in predicted future basal area for the range of climate conditions experienced by these stands highlighting red maple’s wide tolerance of environmental conditions across the region.


1994 ◽  
Vol 70 (4) ◽  
pp. 385-394 ◽  
Author(s):  
W. M. Stiell ◽  
C. F. Robinson ◽  
D. Burgess

Understory 55-year-old white pine (Pinus strobus L.) in mixedwood stands were released in 1971 from an (ca. 80-year-old) overstory of intolerant hardwoods using wheeled skidders in a commercial logging operation. The main aim of the study was to increase the growth and yield of white pine for sawlogs over the following 20 to 30 year period by releasing suppressed pine. Growth of released, healthy white pine was assessed after logging for a range of stand densities (basal areas of 6.9, 11.5, 16.1 m2 ha−1) using suitable control plots and a randomized complete block design with five replicates. Plots were remeasured 10 and 20 years after treatment. By harvesting, much of the natural mortality associated with these stands over the 20-year-period was utilized. Growth responses associated with overstory release were highly significant and demonstrated an 80% increase in sawlog volume increment for treated stands after 20 years. Herb diversity was higher in treated stands and browse potential was not affected. However, white pine regeneration was unacceptably low in all cases. Overstory release increased the natural rate of succession in these stands, but without further management activities or wild-fire, the study area will revert to the economically lower-valued hardwoods. Key words: white pine, growth and yield, mixedwood management, understory release, ecosystem response


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