EFFECT OF MECHANICAL HARVESTING ON YIELD AND QUALITY OF TEA IN TANZANIA

2018 ◽  
Vol 55 (04) ◽  
pp. 560-574
Author(s):  
S. RUTATINA ◽  
R. H. V. CORLEY

SUMMARYHand plucking of tea is labour intensive, and with rising labour costs mechanical harvesting (MH) is of increasing interest. However, effects of MH on yield and quality of tea remain unclear. We harvested two tea clones for eight years with a small, wheeled machine, to investigate effects of different cutting heights on yield and quality. The harvest interval for machine plots was 40% longer than for hand plucking in the first three years and 100% longer thereafter. The yield response, relative to hand plucking, depended on cutting height. Provided that increase in bush height (table rise) was 6 cm per year or less, yields were 15–21% higher than with hand plucking and increased yield was still being maintained after eight years. The increase in yield appeared to be mainly attributable to the longer harvest interval for machine plots, so that larger shoots were harvested. There was no increase in the number of shoots harvested per year, despite more intensive plucking with the machine. In less intensively harvested plots, where table rise was 11–14 cm per year, yield was reduced compared to hand plucking, and shoot number was nearly 30% lower. Dry matter production was greatest under the least intensive harvesting, but greater intensity gave higher harvest index and yield. In plots with no table rise, but not in other plots, a large amount of die-back of plucked points was observed. This may indicate source limitation of shoot numbers. We conclude that, with an extended harvest interval and careful management of cutting height, the yield of tea can be maintained under MH. There was a reduction in green leaf quality, with coarser shoots and increased mature leaf, but a limited number of taster evaluations of quality of the black tea showed significant differences for only one clone.

2016 ◽  
Vol 3 ◽  
pp. 48
Author(s):  
Carlos Rodríguez ◽  
Juan A. Quiñones ◽  
Rodrigo Arias

The trial was conducted at the Centro de Producción Agrícola of ICfA in Cuyuta, Escuintla-Guatemala in order to generate information on the yield and quality of edible mulberry (Morus sp.) roughage treatments consisted of three harvest frequencies (6; 9 and 12 weeks and three fertilization levels of nitrogen (0.40 and 80 kg/ha). A complete randomized block experimental design, with a factorial arrangement (3x3) was used. The cutting height was 0.3 m above the ground level with two sequencies: from August 2nd to September 13 th and from September 13th to December 6th, 1990. In both cases, the 12 week frequency cutting and 80 kg of N were superior to the others (P<=0.01), yielding 6.87 and 6.15 t/ha of dry matter respectively. The yields at 9 weeks were statistically higher than those at 6 weeks. The highest protein percentage of the whole plant, leaves and stalks were produced at 6 weeks. The dry matter digestibility values in vitro showed little variability among treatments, with averages for whole plants, leaves and stalks of 65, 91 and 41 %, respectively. The preceeding data suggests that the mulberry has an excellent potential as a balanced supplement (protein and energy) for dual purpose cattle on the Southern coast of Guatemala.


1977 ◽  
Vol 17 (88) ◽  
pp. 765 ◽  
Author(s):  
AP Meissner ◽  
AL Clarke

Trials lasting three years were conducted at 27 sites in the south-east of South Australia to examine the responses of mown subterranean clover-ryegrass pastures to repeated annual applications of potassium chloride. At 20 sites, yield of dry matter (DM) was increased by potassium in one or more harvests. Responses were measured in 9 out of 55 winter harvests and 42 out of 86 spring harvests; mean responses to 100 kg ha-1 KCl (-Y100) at responsive sites were 380 and 560 kg DM ha-1 in winter and spring respectively. When potassium dressing increased yield, the proportion of clover in the sward was either maintained or increased. The herbage concentration of potassium was usually increased, and its magnesium concentration sometimes depressed, by potassium application. Although the K:Mg ratio was thereby increased, especially during winter, it rarely reached 15, the value considered necessary to induce grass tetany in cattle. Multivariate regression analysis showed that the exchangeable potassium concentration (Kex) of the top 10 cm of soil, the depth of soil overlying clay or limestone, and the sand content of the topsoil were factors affecting yield response. The best regression equations, however, explained less than half of the response variations. In practice, Kex alone would have usefully diagnosed potassium responsive sites. Responses occurred often when Kexwas less than 0.2 me 100 g-1 and rarely when it was greater. The use of potassium fertilizer is likely to be worthwhile to establish new pasture, to maintain the clover content of old pasture, and to increase the yield and quality of hay, where soils have less than 0.20 me 100 g-1 Kex. Such soils are most commonly sands more than 30 cm deep.


1987 ◽  
Vol 67 (3) ◽  
pp. 545-559 ◽  
Author(s):  
W. F. NUTTALL ◽  
H. UKRAINETZ ◽  
J. W. B. STEWART ◽  
D. T. SPURR

In northeastern Saskatchewan on Gray Luvisolic soils, rapeseed (Brassica napus L. and B. campestris L.) grown on many fields does not set seed, possibly because of deficiencies of S and B. Therefore, experiments were begun in 1979 to determine (1) the effect of N, S and B fertilizers on yield and quality of rapeseed; (2) if cultivars (B. napus and B. campestris L.) responded differently to these nutrients; and (3) nutrient and nutrient interaction effects of five rates of N, S and B in a composite rotatable design on yield and quality of the cultivar Regent (B. napus L.). Rates of up to 200 kg N ha−1, 50 kg S ha−1 and 2.8 kg B ha−1 were applied. The experiments were conducted on 13 sites. Nine were in N.E. Saskatchewan on Sylvania f1, Waitville 1 (Luvisolic) and Melfort sicl (Black Chernozemic) soils. Four were in N.W. Saskatchewan on Loon River 1 and Waitville 1, (Luvisolic) soils. In N.W. Saskatchewan there was a significant yield increase because of N (1.00 t ha−1) and S (1.06 t ha−1). In N.E. Saskatchewan on Sylvania f1, rapeseed yields were increased by 0.38 t ha−1 by a combination of S and B and by 0.78 t ha−1 by N. Sylvania f1 soils were lower in soluble B than other experimental sites. At other sites in N.E. Saskatchewan, N but not S increased rapeseed grain yield significantly. Significant response to a combination of S and B was obtained with the cultivar Regent, and both species of rapeseed responded to S fertilizer. Sulphur fertilizer increased the glucosinolate concentration in rapeseed meal at all sites. Sulphur increased oil concentration of rapeseed on all sites except one where frost damaged the crop and increased protein of grain on sites where there was yield response to S. Nitrogen increased protein of rapeseed grown on all sites whereas N combined with B decreased protein and increased oil percentage on all sites except Sylvania f1. The yield response of the cultivar Regent to B was not significantly related to soluble soil B. The combined yield response to S and B in relation to soluble soil S and B was significant (R2 = 0.60). Yield response of rapeseed to S was significantly related to soluble soil S (R2 = 0.35). In conclusion, S fertilizer solved the problem of poor seed set in rapeseed cultivars, but B also enhanced yield by decreasing the number of sterile florets and improving pod development. Key words: Nitrogen, sulphur, boron, rapeseed, oil, protein, glucosinolates


1969 ◽  
Vol 52 (4) ◽  
pp. 281-294
Author(s):  
Modesto Capiel ◽  
Aurelio Sierra Bracero

Two irrigation experiments with cigar-filler tobacco were conducted on the Gurabo Substation Experimental Farm in a field graded for furrow irrigation. The objective was to evaluate the effect of different irrigation frequencies on the yield and quality of two tobacco varieties, P.R. 1-60 and a mosaic resistant line, X-13. Irrigation significantly increased the yield of varieties X-13 and P.R. 1-60. However, in spite that, the yield of P.R. 1-60 tobacco was greater under all treatments; the former showed about three times as much response to irrigation as compared with no irrigation. This variety (X-13) was also responsive to the irrigation level, in spite of light, but well-spaced precipitation between primings. A high incidence of mosaic on P.R. 1-60, which appeared since the fifth priming, probably masked a better response of this variety to irrigation. In an attempt to trace back to plant nutrition the injury caused by mosaic on P.R. 1-60 yields, a linear regression of yield on mineral content of the leaves was carried out, using the individual yield data by experimental units. From an analysis of these data, it seems likely that mosaic caused a yield-limiting effect on P.R. 1-60 as a result of adversely affecting the uptake of minerals by the plant. On the other hand, when observing the highly significant regression of X-13 yields on the moisture content of the leaves and at the same time comparing its regression coefficient (slope) with the corresponding one in variety P.R. 1-60, one may conclude that X-13 made a more efficient use of irrigation which was expressed in greater yield response.


GCB Bioenergy ◽  
2021 ◽  
Author(s):  
Elena Magenau ◽  
Andreas Kiesel ◽  
John Clifton‐Brown ◽  
Iris Lewandowski

jpa ◽  
1995 ◽  
Vol 8 (1) ◽  
pp. 79-83 ◽  
Author(s):  
G. E. Aiken ◽  
S. E. Sladden ◽  
D. I. Bransby

2002 ◽  
Vol 138 (3) ◽  
pp. 317-331 ◽  
Author(s):  
M. J. GOODING ◽  
A. PINYOSINWAT ◽  
R. H. ELLIS

Four field experiments were conducted to investigate the effects of seed rate on yield and quality of wheat. Despite some small and inconsistent effects of seed rate on radiation-use efficiency and harvest index, the responses of PAR interception, above-ground biomass and grain yield generally followed similar asymptotic increases as seed rate increased. In one experiment, when nitrogen fertilizer was withheld, biomass and grain yields did not respond to increases in seed rate despite increases in PAR interception. In one experiment, grain yield followed a parabolic response to seed rate with apparent reductions in yield at very high seed rates. Plants compensated for low population densities by increased production and survival of tillers and, to a lesser extent, increased grain numbers per ear. Net tiller production continued until the main stems flowered or later. Effects of seed rate on grain specific weight and thousand grain weight were small and inconsistent. Hagberg falling number increased linearly with seed rate in three experiments, associated with quicker maturation of the crop. Grain protein concentration declined with increase in sowing rate according to linear divided by linear or linear plus exponential models depending on whether the grain yield response was asymptotic or parabolic. Discolouration of the grain with blackpoint increased with seed rate in the most susceptible cultivar, namely Hereward. The economic consequences of these effects on yield and quality are discussed.


1982 ◽  
Vol 22 (116) ◽  
pp. 244
Author(s):  
DM Whitfield

Tobacco crops were artificially damaged to simulate effects of hail in two series of experiments run over three years. In the first series, four treatments ranging from no damage to complete loss of leaves plus the apex were imposed when 5,10 or 15 leaves had unfolded. The performance of crops replanted or ratooned at the same stages was also measured. In the second series, the effects of lamina loss or midrib damage, or both in crops at early flowering were investigated. The first series showed that yield and quality were drastically reduced by severe damage at the 15 leaf stage. Yields where all the leaves were lost were only 940 kg/ha compared with controls yielding 2400 kg/ha. Replanted crops also yielded poorly at this stage (91 0 kg/ha) but ratooned crops produced satisfactory yields (1840 kg/ha) of good quality leaf. However, ratooning led to significant delays in harvest. In the second series, yields decreased from 2370 and 2030 to 161 0 kg/ha with loss of one-third and two-thirds of the lamina tissue, respectively. Damage to midribs caused additional losses of up to 400 kg/ha. However, only the most severe loss of lamina tissue depressed leaf quality.


AGROFOR ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Tu Trung KIEN ◽  
Mai Anh KHOA ◽  
Tran Thi HOAN ◽  
Tu Quang HIEN

This study was aimed to determine the effect of cutting intervals on leaf yield and quality of the green fodder Trichanthera gigantea used as feed material, mostly in poultry and rabbit diets, in order to improve farm animal products (such as meat and egg). This study included five different formulas (NT) representing five different cutting intervals, namely: NT1: 40 days, NT2: 50 days, NT3: 60 days, NT4: 70 days and NT5: 80 days of cutting intervals. All treatments were allocated in a complete block randomized design; each treatment was repeated 5 times. The other factors such as plantation density, cutting height and fertilizer dosage were similar among the treatments. The obtained results showed that from NT1 to NT5, the leaf dry matter yields were 7.34, 12.13, 12.41, 11.94 and 11.80 tons/ha/year, respectively; crude protein yields were 1.88, 3.13, 3.06, 2.78 and 2.69 tons/ha/year. When the cutting intervals increased from 40 to 80 days, the proportion of dry matter in the fresh leaves increased from 12.91% to 21.04%, crude protein proportion on dry matter decreased from 25.56% to 22.77%; crude fiber proportion on dry matter increased from 9.92% to 12.50%. Based on statistical analysis of dry matter yield and leaf chemical composition of green fodder T. gigantea, it is recommended that the most suitable cutting intervals for Trichanthera gigantea should be 50 – 60 days.


Sign in / Sign up

Export Citation Format

Share Document