Dolomite

According to interviews with smallholders, conducted by Euler et al. [unpublished data], the rubber and oil palm plantations in the clay Acrisol soil were planted after clearing and burning the previous forest or logged forest. In the loam Acrisol soil, oil palm plantations were established after clearing and burning the previous jungle rubber whereas the rubber plantations were established from previously logged forest. Based on our interviews, only the oil palm plantations were fertilized during our study year, 2013, while the rubber plantations were not. Oil palm plantations in the clay Acrisol soil were fertilized once in the rainy season (October to March), and in the loam Acrisol soil, these were fertilized once in the rainy season and once in the dry season (April to September). The most commonly used fertilizers were NPK complete fertilizer (i.e. Phonska, Mahkota), potassium chloride (KCl) and urea (CO(NH₂)₂). Fertilizer additions to the oil palm plantations ranged from 300 kg NPK-fertilizer ha^-1 year^-1 (for those plantations that were fertilized once) to 550 kg NPK-fertilizer ha^-1 year^-1 (for those plantations that were fertilized twice). In terms of unit nutrient element added, these rates were equivalent to 48–88 kg N ha^-1 year^-1, 21–38 kg P ha^-1 year^-1 and 40–73 kg K ha^-1 year^-1. Additionally, three of the smallholders applied 157 kg K-KCl ha^-1 year^-1 and 143 kg Cl-KCl ha^-1 year^-1 and two of the smallholders applied 138 kg urea-N ha^-1 year^-1. One of the smallholders also applied lime in 2013 at an average rate of 200 kg dolomite ha^-1 year^-1. Both manual and chemical weeding took place throughout the year at the rubber and oil palm plantations. The most commonly used herbicides were Gramoxone and Roundup; these were applied at an average rate of 2 to 5 L herbicide ha^-1 year^-1 [Euler et al. unpublished data].

A total of 29 Australian A. lentis isolates were assessed (Table 2) in this experiment. These were predominately isolated in South Australia from field plants or seed stocks in 2010, 2011, and 2012. The other isolates were from field plants from Victoria isolated in 2012 with the exception of the two reference isolates Kewell and AL4. Most isolates were from lentil cvs PBA Flash and Nipper, three were from cv Nugget, two from cv Northfield and one from cv Aldinga. Inoculum was prepared as described above and the concentration adjusted to 10⁶ spores per ml before adding a drop of Tween 80 (Merck Pty. Ltd.). Control seedlings were sprayed with sterile water plus Tween 80. Plants were inoculated until runoff using a 500 ml hand sprayer producing a fine mist, and the pots rotated during the procedure to achieve an even spread of inoculum. The host differential set consisted of ILL7537, cvs Northfield, Indianhead, Nipper, PBA Flash and the susceptible check ILL6002. Each accession was sown as five seeds per 5 cm forestry tube filled with a 1:1 pine bark/sand mix, ameliorated with dolomite to achieve pH 7.0, and grown in a growth room at 20°C with a 12 h photoperiod. After 2 weeks, these were thinned to three seedlings per pot immediately prior to inoculation. Seedlings were watered to field capacity twice a week, and fertilized weekly from 2 weeks old with Nitrosol (Amgrow) as per the manufacturer's instructions.
The 29 isolates were tested using three separate randomized, nested, complete block design trials. Each trial assessed three plants/accession/treatment and trials were repeated three times (total of four replicates). There were 12 treatments per trial consisting of nine unknown isolates, two positive control isolates (AL4 and Kewell) and one uninoculated control. The following method was adapted from those previously used (Nasir and Bretag, 1997a (link); Ford et al., 1999 (link); Sambasivam, 2011 ) to promote infection and maintain conditions for disease development. The six pots, each containing a different accession, were placed randomly in a solid 2 L plastic container, assigned a treatment, inoculated as described above then placed randomly in one of two 200 L plastic crates to minimize air flow present in the growth room. The crate also contained water (2–4 cm depth) to maintain humidity. The crate was covered tightly with a lid and wrapped in black plastic for 48 h post inoculation to provide dark conditions with 100% humidity to promote infection. After removal of the coverings, the crates were misted three times a day and covered with damp hessian for 48 h each week to provide conditions conducive to disease. The growth room conditions were the same as those described above for seedling production.
Final disease assessment was made on whole plants 28 days after inoculation (dai) when discrimination of disease reaction between susceptible and resistant plants was distinct (Ford et al., 1999 (link)). One observation was made from each seedling. The subjective 1–9 disease index used by previous researchers (Nasir and Bretag, 1997a (link); Ford et al., 1999 (link); Sambasivam, 2011 ) was modified by specifying a size limit of small lesions and percentage leaf drop. The scores were: 1 = no visible disease symptoms; 3 = leaf lesions only, chlorosis of affected leaves, < 10% leaf drop; 5 = leaf lesions, up to 25% leaf drop, stem flecks or lesions < 2 mm; 7 = leaf lesions, up to 50% leaf drop, stem lesions > 2 mm; 9 = leaf lesions, potential defoliation, stem girdling, potential plant death.
Statistical analysis was performed using GenStat® version 16. Data from all three trials were then pooled and analyzed using Linear Mixed Model analysis. The use of the same two controls in each trial provided a means of ranking isolates across trials. Data from control seedlings was excluded from all analyses to prevent bias since the scores were consistently 1. Means of disease score were calculated for isolates, cvs and the isolate /cv interaction using Least Square Difference (LSD) 5%. Interaction plots for each of the three trials were performed using Minitab 16 Statistical Software to provide a means of observing deviations from common patterns of interaction. Mean with 95% confidence limit was used to compare aggressiveness of isolates originally isolated from cv PBA Flash or cv Nipper. Mean scores were used to place isolate reactions on cultivars into categories of Resistant (score 1), Moderately Resistant (score 1.1–4.9), Moderately Susceptible (score ≥ 5–6.0) or Susceptible (score > 6.0) (Nasir and Bretag, 1998 (link)).

According to the level of sanding with the differences in color, rock mass structure, microscopic features, alterations, rock mass integrity indexes, rock quality designation (RQD), wave velocity ( $V_P$ ), the intactness index of rock mass ( $k_v$ ), dolomites can be divided into four types of sanding: fierce, strongly, medium and weakly (micro-new rock mass), as listed in Table 1^{1 ,61 (link)}.Table 1

Sandy degree of dolomite classification^{1 ,61 (link)}.

Sandy degree	Color	Rock organization structure	Volume change	Microscopic feature	Alteration	Rock main characteristics value
Fierce sandy	Uniform discoloration and gloss loss	Totally destroyed and disintegrates and decomposes into loose sand particles	Large	Powder crystal structure	Except for quartz, most of the residual minerals alter to secondary minerals	Kv < 0.10 Vp < 1.0 km/s
Strongly sandy	Primary discoloration with part of rock blocks retaining their original color	Mostly destroyed and small part disintegrates and decomposes into loose sand particles	Not small	Fine crystal—medium crystal structure	Except for quartz, feldspar, mica, and femic minerals are already weathered	RQD < 20% Kv = 0.10 ~ 0.15 Vp = 1.0 ~ 2.0 km/s
Medium sandy	Mostly discoloration and only the fracture of the rock retain slight discoloration as bright color	Mostly appear clear and complete, and the body of rock exhibits fragmentation; small part appears embedded and exhibits fragmental structure	No	Aplitic texture	Femic minerals exhibit oxidation and corrosion; feldspar exhibits opacification	RQD = 20% ~ 40% Kv = 0.15 ~ 0.35 Vp = 2.0 ~ 3.5 km/s
Weakly sandy	Uniform slight discoloration as bright color	All appear original withcomplete organization structure	No	Medium crystal structure	Only the part along with the crack appear the phenomenon of weathering and alteration or/and the immersion of the corrosion	RQD > 50% Kv > 0.40 Vp > 4.0 km/s

In this study, the Sandy Dolomite along and near the Yuxi section of the CYWD Project was taken as the research object. Dolomite with various sandification grades was sampled in field outcrops, boreholes, and tunnels to determine the PMP. The test results are displayed in Table 2, Figs. 2, and 3.Table 2

Statistics of ρ and n of Sandy Dolomite.

Sandy Dolomite	Number of tests	ρ (g/m3)			n (%)
		Min	Max	Mean	Min	Max	Mean
Fierce	19	1.7	1.9	1.82	9.09	23.08	16.63
Strongly	24	2.442	2.608	2.549	5.53	11.62	8.59
Medium	90	2.62	2.761	2.699	0.77	4.45	2.577
Weakly	68	2.601	2.797	2.723	0.34	3.26	1.426

Figure 2

Relationship between Sandy Dolomite and n.

Figure 3

Relationship between Sandy Dolomite and ρ.

According to Matula’s method⁶² , fierce Sandy Dolomite is a rock with low density and high porosity; strongly Sandy Dolomite is a rock with medium density and porosity; medium and weakly Sandy Dolomite is a rock with high density and low porosity.
According to Figs. 2 and 3, the higher the sandification grade increases, the higher porosity and the lower density of Sandy Dolomite, indicating that the sandification grade increases with the rise of porosity and the decline of density.
Since the fierce Sandy Dolomite can be easily crushed by hand, a complete rock block cannot be obtained for mechanical testing, as shown in Fig. 4a. The thin rock section identification is shown in Fig. 4b. The indoor size distribution test result shows that the fierce Sandy Dolomite is in a state of silty fine sand.Figure 4

Fierce Sandy Dolomite (E 102°41′38.34″, N 24°35′48.82″). (a) Field tests Photos. (b) Thin Section Identification (“Dol” is the abbreviation for “dolomite”, “Are” is the abbreviation for “argillaceous”).

Since the rock mass strength of strongly Sandy Dolomite is obviously weakened, with forming weathering fissures, a complete rock block cannot be obtained for mechanical testing, as shown in Fig. 5a. The thin rock section identification is shown in Fig. 5b. Schmidt rebound test on the strongly Sandy Dolomite sample shows that there is no rebound reading, indicating that the rock mass has been damaged.Figure 5

Strongly Sandy Dolomite (E 102°39′48.92″, N 24°15′33.16″). (a) Field tests Photos. (b) Thin Section Identification (“Dol” is the abbreviation for “dolomite”, “Iron” is the abbreviation for “Iron sludge”).

In view of the aforementioned condition, this study only took the medium and weakly Sandy Dolomite as the research objects and analyzed the relationship between UCS and SH, I_s(50), V_p, ρ, and n. The PMP of rock samples were tested using the methods specified by ISRM by establishing at least six sets of samples for each rock sample and calculating their average value.