Abstract: Gladiolus is an important cash crop and is grown
mainly for its elegant spikes. Traditionally the gladiolus corms are
planted manually which is very tedious, time consuming and labor
intensive operation. So far, there is no planter available for planting
of gladiolus corms. With a view to mechanize the planting operation
of this horticultural crop, a prototype of 4-row gladiolus planter was
developed and its performance was evaluated in-situ condition. Cupchain
type metering device was used to place each single gladiolus
corm in furrow at required spacing while planting. Three levels of
corm spacing viz 15, 20 and 25 cm and four levels of forward speed
viz 1.0, 1.5, 2.0 and 2.5 km/h was taken as evaluation parameter for
the planter. The performance indicators namely corm spacing in each
row, coefficient of uniformity, missing index, multiple index, quality
of feed index, number of corms per meter length, mechanical damage
to the corms etc. were determined during the field test. The data was
statistically analyzed using Completely Randomized Design (CRD)
for testing the significance of the parameters. The result indicated
that planter was able to drop the corms at required nominal spacing
with minor variations. The highest deviation from the mean corm
spacing was observed as 3.53 cm with maximum coefficient of
variation as 13.88%. The highest missing and quality of feed indexes
were observed as 6.33% and 97.45% respectively with no multiples.
The performance of the planter was observed better at lower forward
speed and wider corm spacing. The field capacity of the planter was
found as 0.103 ha/h with an observed field efficiency of 76.57%.
Abstract: Riprap is mostly used to prevent erosion by flows
down the steep slopes in river engineering. A total of 53 stability tests
performed on angular riprap with a median stone size ranging from
15 to 278 mm and slope ranging from 1 to 40% are used in this study.
The existing equations for the prediction of medium size of angular
stones are checked for their accuracy using the available data.
Predictions of median size using these equations are not satisfactory
and results show deviation by more than ±20% from the observed
values. A multivariable power regression analysis is performed to
propose a new equation relating the median size with unit discharge,
bed slope, riprap thickness and coefficient of uniformity. The
proposed relationship satisfactorily predicts the median angular stone
size with ±20% error. Further, the required size of the rounded stone
is more than the angular stone for the same unit discharge and the
ratio increases with unit discharge and also with embankment slope
of the riprap.